Since 2015, the agricultural “insurance+futures” mode has rapidly spread across the country, triggering widespread calls for financial subsidy support. In view of the liquidity constraints in the domestic agricultural futures market, this study conducts an in-depth discussion on the scale and method of financial subsidies for the “insurance+futures” mode. Taking corn as the research object, this paper first establishes a quantitative theoretical model of financial subsidies under liquidity constraints in the futures market. Based on the data after the reform of temporary corn purchase and storage policy in 2016, the empirical analysis finds that the carrying scale of the corn futures market for the “insurance+futures” mode is extremely limited, accounting for only 14.4〖WTXT〗%〖WTBZ〗 of the national total output. This indicates that the mode is not suitable for large-scale financial subsidies for the time being.The study further puts forward the implementation strategy of financial subsidies by steps, regions and stages, and suggests corresponding supporting measures.