The invention relates to a method for measuring disymmetrical section impact load of a beam and belongs to the field of measurement of load of an airplane design mechanical structure. The method comprises the following steps: A) determining a section, needing to be measured, of a structural beam, wherein the section must be a disymmetrical section; B) on the determined disymmetrical section, selecting the surface, which two symmetrical shafts pass through, of a test sample and sticking right-angled strain flower sheets to the surface; C) measuring the strain values of four flower sheets underthe actual working state; D) obtaining the elastic modulus E and the Poisson's ratio of the structural beam material by aiming at the common round section and the ring section, and calculating the section load by utilizing the corresponding formula; and E) for the common disymmetrical section, enabling the method to be consistent with the round or ring section calculation method except for the torque load of the section, calibrating the torque load of the section, and backstepping the section load by calibrating the relation between the load and the strain.