Why does WeChat only display micro signals but not mobile phone numbers?

You can set it. If you want to display, you don't need to set it.

If you don't want to display your own number, you can set it by the following methods:

First, update WeChat to version 5.2, click the option in the upper right corner of WeChat homepage, find the "Settings" option in the options, and click to enter the settings.

After setting My Account, the current account protection will be displayed, as shown in the figure below. Click "My Account" to enter "Account Protection" on the new page to set account protection.

To set account protection, you must first bind the mobile phone number. If the mobile phone card and WeChat are on the same device, click Bind Mobile Phone Number, and then enter the local mobile phone number. Next, the system will automatically set account protection and bind the account with the mobile phone. And send a short message to the mobile phone, and the account protection is set successfully.

If the mobile phone card and WeChat account are not in the same device, enter the verification code received by the other mobile phone into the device protected by WeChat account, and click Next to complete account protection.