As to China with the characteristic of huge population and limited arable land, grain production has always been the most fundamental issue to national interests and people’s livelihood, so China’s government constantly enact food policy to promote and secure grain production. Based on the viewpoint of macro perspective, the paper firstly summarized the historical changes of food policy in China, secondly elaborated the status quo of the food policy, and thirdly made Granger Causality Test for food policy impact on grain production. Granger Causality Test result shows that fiscal expenditure for agriculture is granger cause for growth of grain production, so that it proves the positive role of the food policy on grain production. At last, the paper put forward suggestions for improving food policy in the future.