The present invention discloses a method for measuring the impact load of a thin-walled beam with double-symmetrical cross-section openings. The method comprises the following steps: S1, establishinga coordinate system: selecting the centroid of a cross-section of the thin-walled beam with double-symmetrical cross-section openings as the coordinate origin o, wherein the x-axis is towards the right along one of the symmetry axes, the y-axis is upwards along another symmetrical axis, and the direction of the z-axis is determined according to the right-hand rule; S2, measuring the strain of eachstrain flower on a certain cross-section of the thin-walled beam with double-symmetrical cross-section openings, and according to the linear elastic superposition theory, superposing the measured strains to calculate a stress value corresponding to the impact load; and S3, according to the stress value calculated in step S2, calculating the impact load on the cross-section. According to the method provided by the present invention, the problem of load measurement when the thin-walled beam with double-symmetrical cross-section openings is subjected to the impact is solved, the measurement result is true and reliable, and reliable impact load data can be provided for simulation calculation.