My phone contacts in my mobile has gone because my son do it unpurposely. How to reinstall all my phone contacts excpet sims contact?

Normally the first choice would be restoring from backups, if you have backed up your phone before.
Just notice that restoring from backup means your whole phone data will be replaced by the backup. If there are different files between backup and phone, you need be cautious.
If there is no backup, it does not mean no way to recover the deleted contacts. As long as they are not overwrote, we can find them by virtue of PhoneRescue - a data recovery application for both Android and iOS.
This tool is easy to use, with several minutes you can get your deleted contacts back.
For detailed steps to restore phone contacts with PhoneRescue, follow the guide.

The only way to restore your phone contact is if you have previously created a backup of your contacts otherwise there is no way to restore your contacts. But if you have created a backup previously then you would just use the previously created backup to restore your contacts.