Global food security faces serious challenges of climate change. Accurately assessing the impacts of climate change on grain yield is the key to the formulation of agricultural adaptability. Many research methods have been used in practice,so the advantages,disadvantages and applicability of these methods need to be clarified in order to promote their development,integration and improvement. Using the methods of literature,induction and comparative law,this article classified the related research methods into five types and summarized their applicability. The result shows that the yield division methods can be used to analyze the relationships between grain yield and climatic factors at different growth stages; the experimental methods are generally used for the sensitivity analysis of grain yield to climatic factors; the production function methods are suitable for analyzing the marginal effect of climate change on food production; climatic productivity models focus on the assessment of changes in agricultural production environment,while crop growth models can predict the impact of climate change on food production by incorporating climate scenarios. The defects of these methods include the difficulties of simulating technical yields, weak anti-interference ability,omitted variables,overly complex functions,non-verifiability of conclusion,problems in calibrating parameters,scale effect of models,etc. With the development of research on mechanism,the forecasting models of grain yield will experience a transition from the crop models to the climate-hydrology-crop-economic models. In addition,multi-source data fusion and multi-objective models have provided important clues to the innovation of research methods.