Multiple Loans

In California, If an auctioned property has 3 loans on it and the lender of the first loan auctioned the house. whether the buyer needs to pay the remaing 2 loan amount also?

If by auction you mean the trustee sale auction, the junior loans will have their security interest in the property wiped out - so no the buyer will not need to pay them. Just make sure they are actually junior and that no subordination agreement has been filed.