Abstract: Crop residues burnt in open field is not only a waste of agricultural resources, but also a serious damage to the ecological environment. Mechanized straw returning is an important way for comprehensive utilization of straw, with good ecological and economic benefits. In our country, Jiangsu province and other places, the government has given fixed subsidies to mechanized straw returning in recent years. Through analyzing the different ways of the subsidy policy of returning straw to farmland, comparing the foreign government"s experience of payments for ecological service (PES), Straw subsidy policy can be optimized from the following aspects:Vigorously develop agricultural machinery service market, Scientifically formulating ecological compensation standard, paying attention to cultivating third-party organization and giving full play to the role of market mechanism.