diff --git a/docs/API_reference/en/iotlib/voiceCall.md b/docs/API_reference/en/iotlib/voiceCall.md
index 4f6a42af29037c2563c20db7640755e84c2c17f0..5c393e5da731af55da30a93e2b47a72db4201d3f 100644
--- a/docs/API_reference/en/iotlib/voiceCall.md
+++ b/docs/API_reference/en/iotlib/voiceCall.md
@@ -366,7 +366,7 @@ Sets DTMF tone.
 
 >This method takes effect only during a voice call.
 >
->Multiple characters can be sent at a time (after 2023/9/12, a maximum of 6 characters can be sent at a time).
+>Multiple characters can be sent at a time (after 2024/4/2, a maximum of 6 characters can be sent at a time).
 
 
 
diff --git a/docs/API_reference/zh/iotlib/sim.md b/docs/API_reference/zh/iotlib/sim.md
index c26039d2528dff7c137d6a4368077819d4605536..3e0f5ad9dec28d6dda97cbd202c2c741d8b28dc2 100644
--- a/docs/API_reference/zh/iotlib/sim.md
+++ b/docs/API_reference/zh/iotlib/sim.md
@@ -565,7 +565,11 @@ sim.switchCard(simId)
 
 >支持该方法的模组：
 >
->EC800MCN_LE/EC800MCN_LA/EC800MCN_LF/EC600MCN_LF/EC600MCN_LA/EC600MCN_LE/EC600MCN_CC/EG810MCN_GA/EC600ECN_LC。
+>EC800MCN_LE/EC800MCN_LA/EC800MCN_LF/EC600MCN_LF/EC600MCN_LA/EC600MCN_LE/EC600MCN_CC/EG810MCN_GA/EC600ECN_LC/EC800GCN_LD。
+>
+>注意当目标卡是当前卡时，[`sim.switchCard`](https://python.quectel.com/doc/API_reference/zh/iotlib/sim.html#%3Ccode%3Esim.switchCard%3C/code%3E)直接返回-1，不触发此接口设置的回调函数。
+>
+>部分模组（如EC800GCN_LD系列）无法检测sim卡2是否已经插入，当sim卡2不存在时，允许切卡到sim卡2。
 
 
 
@@ -671,9 +675,9 @@ def usrFun(args):
 
 > 支持该方法的模组：
 >
-> EC800MCN_LE/EC800MCN_LA/EC800MCN_LF/EC600MCN_LF/EC600MCN_LA/EC600MCN_LE/EC600MCN_CC/EG810MCN_GA/EC600ECN_LC。
+> EC800MCN_LE/EC800MCN_LA/EC800MCN_LF/EC600MCN_LF/EC600MCN_LA/EC600MCN_LE/EC600MCN_CC/EG810MCN_GA/EC600ECN_LC/EC800GCN_LD。
 >
-> 注意以下几点：<br>1、目标卡不存在或者目标卡状态异常；<br>2、目标卡是当前卡；<br>以上情况切卡方法[`sim.switchCard`](https://python.quectel.com/doc/API_reference/zh/iotlib/sim.html#%3Ccode%3Esim.switchCard%3C/code%3E)直接返回-1，不触发此接口设置的回调函数。
+> 注意当目标卡是当前卡时切卡方法[`sim.switchCard`](https://python.quectel.com/doc/API_reference/zh/iotlib/sim.html#%3Ccode%3Esim.switchCard%3C/code%3E)直接返回-1，不触发此接口设置的回调函数。
 
 
 
diff --git a/docs/API_reference/zh/iotlib/voiceCall.md b/docs/API_reference/zh/iotlib/voiceCall.md
index 7b2671a6b15375bd9b6899811f352f2932ac748f..bc318e09f51fdd1f9047b0458b7790da8acd591a 100644
--- a/docs/API_reference/zh/iotlib/voiceCall.md
+++ b/docs/API_reference/zh/iotlib/voiceCall.md
@@ -349,7 +349,7 @@ voiceCall.startDtmf(dtmf, duration)
 
 >该方法仅在语音通话过程中使用生效
 >
->支持单次发送多个字符（2023/9/12之后单次最多发送6个字符。）
+>支持单次发送多个字符（2024/4/2之后单次最多发送6个字符。）