Generally, the repayment ability needs to be more than twice that of the loan, otherwise the bank can't prove that you have the repayment ability, and you can't get the loan.

As you said, the loan is 500,000 yuan, which will be repaid in 20 years, with a monthly payment of 3,272.22 yuan. It's almost enough for the total amount of husband and wife to reach 6500 yuan, but the bigger the total amount, the better, which proves that you have the ability to repay and it is better to borrow money.