@Xiaojun0 The 1042-S is the gross earnings that has not been reduced by the host fee Airbnb deducted. It also has not been reduced by the refunds to sent to guest via resolution but includes all money you received from guests via resolution (money request), other fees like pet fee and cleaning fee etc. You will have to deduct those from the 1042-S total or you will overstate your net income. Below is the reply I got from Airbnb support which by the way is pretty good.
Per IRS requirements, a gross earnings report would not include the deduction of service fees, refunds, adjustments, etc. Any cleaning fees, rental commissions, insurance, and other transactions that are processed as payouts would be considered gross earnings. You can find this and more information in our Help Center article here:
https://www.airbnb.com/help/article/182
Though these amounts may or may not be taxable income to you on your U.S. Income Tax Return, we are required to report them. We encourage you to consult with a tax advisor to determine how these items should be treated for tax purposes.