In this paper, we take a civil aircraft as the research object, establish a gust calculation model for the aircraft, and introduce corresponding control law models to calculate and compare discrete gust loads under open loop and closed loop conditions. At the same time, the differences and reasons for the gust incremental loads on the main lift surface under different calculation inputs are studied. Research has shown that considering control laws in load design can have a certain impact on the gust loads of different components of the aircraft, and the specific calculation results are related to the logic of control law design. At the same time, there are significant differences and certain patterns in the calculation results under different calculation inputs. Early variable parameter analysis can effectively improve the efficiency of gust load design and evaluation.