我说的你不信，看看别人说的

http://www.mortgage-calc.com/free-calculator/mortgage/how-to-qualify-for-a-mortgage-when-youre-self-employed/

Tax deductions can hurt you.

Lenders look at net income, not gross income, so business tax deductions lower your qualifying income for your mortgage when you’re self-employed. If this standard seems unfair, it really isn’t — money that you’re spending on your business is money you don’t have to pay your mortgage.

That being said, some lenders may allow certain tax deductions — like depreciation, amortization, casualty losses and loss carryovers — to be added back to net income for qualification purposes.