In the test of the flexural performance of the honeycomb sandwich structure, due to the different test methods, there is a situation that the data dispersion is large, which causes the reliability to be reduced, which is not conducive to the evaluation of the true performance of the structure. The flexural performance of the honeycomb sandwich structure was studied by flexural method measurement; flexural performance average method analysis and lateral pressure method, and the discrete difference of data was compared to evaluate the effectiveness of the three test methods. Through the test and analysis of the test pieces, the flexural performance data of the honeycomb sandwich panel is obtained. The results show that: the dispersion coefficient of the flexural performance data measured according to the ASTM method is greater than 0.1, which conceals the authenticity of the test results; according to the mean value of the flexural performance The method substituting the honeycomb core shear modulus into the relational formula to solve the flexural performance of the sandwich structure, the dispersion coefficient is less than 0.09, the result is credible; according to GB/T 1454-2005 lateral compression method, the lateral compression modulus of the sandwich structure is lower than that of flexural test, considering the influence of the stiffness of the panel itself, the result of the lateral pressure method is more authentic and the dispersion coefficient is less than 0.07, which is credible The degree is further improved.