Can Shanghai only pay the provident fund without paying social security?

Sure, are you from outside? Non-Shanghai residents need to meet three conditions when buying houses in Shanghai:

1. The buyer is married.

2. Buyers originally had no room in Shanghai.

3. Pay personal income tax or social security for 5 years or more continuously from the date of purchase.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.