My Mac suddenly disconnects to WiFi

As there is very little usable Technical Information to work from.

Below is a best guess

1 - Restart the Router

2 - Refer to next link from Apple Suggested on suggested Wifi Setting Recommended settings for Wi-Fi routers and access points - Apple Support

3850AmberJack wrote:

Mac disconnects and then reconnects all the time

Please provide some problem details and context.

Writing an effective Apple Support Commun… - Apple Community

Please solve this’s problem

mac WiFi network unsecured

You need to setup security on your Router, Modem, or Hotspot, which exact one do yo have?