diff --git a/GeoPulse Pipeline/GeoPulse Pipeline.csproj b/GeoPulse Pipeline/GeoPulse Pipeline.csproj
index 391d8b4..1803278 100644
--- a/GeoPulse Pipeline/GeoPulse Pipeline.csproj	
+++ b/GeoPulse Pipeline/GeoPulse Pipeline.csproj	
@@ -10,6 +10,7 @@
     <ItemGroup>
         <PackageReference Include="Confluent.Kafka" Version="2.14.0" />
         <PackageReference Include="Dapper" Version="2.1.72" />
+        <PackageReference Include="Elastic.Clients.Elasticsearch" Version="9.3.6" />
         <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="8.0.5" />
         <PackageReference Include="Npgsql" Version="10.0.2" />
         <PackageReference Include="Npgsql.DependencyInjection" Version="10.0.2" />
diff --git a/GeoPulse Pipeline/KafkaConsumer.cs b/GeoPulse Pipeline/KafkaConsumer.cs
index 0466806..1607058 100644
--- a/GeoPulse Pipeline/KafkaConsumer.cs	
+++ b/GeoPulse Pipeline/KafkaConsumer.cs	
@@ -1,6 +1,7 @@
 using System.Data;
 using System.Text.Json;
 using Confluent.Kafka;
+using Elastic.Clients.Elasticsearch;
 using Npgsql;
 
 namespace GeoPulse_Pipeline;
@@ -10,15 +11,22 @@ public class KafkaConsumer : BackgroundService
 	private readonly ILogger<KafkaConsumer> _logger;
 	private readonly NpgsqlDataSource _dataSource;
 	private readonly string _kafkaHost;
+	private readonly ElasticsearchClient _esClient;
 
 	private const int BatchSize = 1000;
 	private readonly TimeSpan MaxWaitTime = TimeSpan.FromSeconds(2);
 
-	public KafkaConsumer(ILogger<KafkaConsumer> logger, IConfiguration configuration, NpgsqlDataSource dataSource)
+
+	public KafkaConsumer(
+		ILogger<KafkaConsumer> logger,
+		IConfiguration configuration,
+		NpgsqlDataSource dataSource,
+		ElasticsearchClient esClient)
 	{
 		_logger = logger;
 		_kafkaHost = configuration["KafkaHost"];
 		_dataSource = dataSource;
+		_esClient = esClient;
 	}
 
 	protected override async Task ExecuteAsync(CancellationToken stoppingToken)
@@ -28,7 +36,7 @@ public class KafkaConsumer : BackgroundService
 		var consumerConfig = new ConsumerConfig
 		{
 			BootstrapServers = _kafkaHost,
-			GroupId = "telemetry-db-writer-group", // 💡 建議換個名字，強迫 Kafka 重置 Offset
+			GroupId = "telemetry-db-writer-group",
 			AutoOffsetReset = AutoOffsetReset.Earliest,
 			EnableAutoCommit = false
 		};
@@ -42,7 +50,7 @@ public class KafkaConsumer : BackgroundService
 		var buffer = new List<ConsumeResult<Ignore, string>>();
 		var lastBatchTime = DateTime.UtcNow;
 
-		_logger.LogInformation("🚀 Consumer 已啟動，開始監控 Kafka 訊息...");
+		_logger.LogInformation("Consumer 已啟動，開始監控 Kafka 訊息...");
 
 		while (!stoppingToken.IsCancellationRequested)
 		{
@@ -63,6 +71,7 @@ public class KafkaConsumer : BackgroundService
 					_logger.LogInformation($"[處理中] 準備批次寫入 {buffer.Count} 筆資料...");
 
 					await BulkInsertToDatabaseAsync(buffer, stoppingToken);
+					await BulkInsertToElasticsearchAsync(buffer, stoppingToken);
 
 					var offsets = buffer.GroupBy(msg => msg.TopicPartition)
 						.Select(g => new TopicPartitionOffset(g.Key, g.Last().Offset + 1)).ToList();
@@ -90,6 +99,7 @@ public class KafkaConsumer : BackgroundService
 		CancellationToken stoppingToken)
 	{
 		var jsonOptions = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
+
 		await using var batch = _dataSource.CreateBatch();
 
 		foreach (var msg in buffer)
@@ -111,4 +121,36 @@ public class KafkaConsumer : BackgroundService
 
 		await batch.ExecuteNonQueryAsync(stoppingToken);
 	}
+
+	private async Task BulkInsertToElasticsearchAsync(List<ConsumeResult<Ignore, string>> buffer,
+		CancellationToken stoppingToken)
+	{
+		var jsonOptions = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
+
+		var documents = new List<object>();
+
+		foreach (var msg in buffer)
+		{
+			var data = JsonSerializer.Deserialize<TelemetryRequest>(msg.Message.Value, jsonOptions);
+			if (data == null) continue;
+
+			documents.Add(new
+			{
+				deviceId = data.DeviceId,
+				timestamp = data.Timestamp,
+				location = new { lat = data.Lat, lon = data.Lng }
+			});
+		}
+
+		var indexName = $"geopulse-telemetry-{DateTime.UtcNow:yyyy.MM.dd}";
+
+		var response = await _esClient.BulkAsync(b => b
+			.Index(indexName)
+			.CreateMany(documents), stoppingToken);
+
+		if (!response.IsValidResponse)
+		{
+			_logger.LogError("寫入 Elasticsearch 失敗: {Error}", response.DebugInformation);
+		}
+	}
 }
\ No newline at end of file
diff --git a/GeoPulse Pipeline/Program.cs b/GeoPulse Pipeline/Program.cs
index 9941d53..1977f43 100644
--- a/GeoPulse Pipeline/Program.cs	
+++ b/GeoPulse Pipeline/Program.cs	
@@ -7,6 +7,7 @@ using Microsoft.AspNetCore.Mvc;
 using Npgsql;
 using Serilog;
 using Serilog.Sinks.Elasticsearch;
+using Elastic.Clients.Elasticsearch;
 
 Log.Logger = new LoggerConfiguration()
 	.MinimumLevel.Information()
@@ -26,6 +27,9 @@ Log.Logger = new LoggerConfiguration()
 
 var builder = WebApplication.CreateBuilder(args);
 builder.Host.UseSerilog();
+var esSettings = new ElasticsearchClientSettings(new Uri("http://192.168.0.110:9200"));
+var esClient = new ElasticsearchClient(esSettings);
+builder.Services.AddSingleton(esClient);
 var kafkaHost = builder.Configuration.GetValue<string>("KafkaHost");
 var producerConfig = new ProducerConfig()
 {