Abstract: With the locust plague in Africa, new coronavirus pneumonia and other public events, food security has once again aroused great concern in the world. Food Security needs high agricultural productivity as a guarantee, and the fiscal expenditure on supporting agriculture plays an obvious role in improving agricultural productivity. Through the analysis of the structure of the central and local fiscal expenditure on supporting agriculture and the structure of the fiscal expenditure on supporting agriculture project, the efficiency of fiscal expenditure on supporting agriculture under the current situation of the division of fiscal expenditure responsibility between the two levels of governments is clarified, thus scientifically dividing the expenditure responsibility of “central government” and “local government”, comprehensively analyzing the influence factors of fiscal expenditure on agriculture on agricultural productivity, and providing mathematical analysis for adjusting fiscal expenditure structure on agriculture.