How does Apple 6s cancel SMS sharing with another mobile phone?

Sharing SMS with another mobile phone is caused by opening iMessage and logging in with the same ID.

The specific steps to cancel SMS sharing are as follows:

1. Click the "Settings" icon on the main screen and click "Information";

2. Click "Send and Accept";

3. Under the option of "Use when starting a new conversation", the device can cancel SMS sharing by checking the "mobile phone number".