Generally speaking, you can try to change your avatar on the smart education platform of Xi Foreign Affairs College according to the following steps:

1. Login platform: First, use your account and password to login to the wisdom education platform of Xi Foreign Affairs University. Usually in the login page, you need to enter your student number/work number and password to enter the platform.

2. Navigate to the profile or settings page: After successful login, you need to navigate to the profile or settings page. Usually, these options can be found in the top navigation bar or sidebar of the platform home page.

3. Find the avatar setting options: On the profile or settings page, you need to find the options related to the avatar. This may be labeled as "changing avatar" or "editing avatar". Click this option to continue the process of changing the avatar.

4. Upload a new avatar: On the page of changing the avatar, you will usually see an area or button to upload the avatar. You can choose a new picture as your avatar from your computer or mobile device. Please note that some platforms may require the size and format of your avatar, and you need to ensure that your avatar meets these requirements.

5. Save the changes: After uploading the new avatar, confirm your satisfaction with the new avatar, and click the "Save" or "Confirm" button to save the changes. The platform may require you to perform additional confirmation steps, such as entering a password or verifying a verification code, to ensure security.

The specific steps may vary depending on the platform version and design. If you encounter any difficulties in changing the avatar, it is recommended that you consult the help document of the platform, contact the technical support team of the platform or consult the relevant departments of the school for specific operation guidance.