Abstract: In view of the demands of the combined dynamic strength assessment of a missile instrument cabin assembly’s structures and equipment, an integral cabin assembly’s dynamic strength test method was studied. A special elastic loading device for overload of the gas cylinder was designed and the equivalent simulation of cylinder overload was realized. Through the whole cabin vibration test boundary simulation and transfer characteristics analysis, the difference between noise excitation vibration transfer and mechanical vibration transfer was verified. Large stiffness simulation boundary, instead of the real boundary of inter-stage, was used to combine with the instrument cabin for combined dynamic strength test. The test conditions of the three key structural parts were proposed, and the combined assessment methods of the structure and equipment in different parts of the cabin were determined by comparing the preliminary test and the normalized input response. This test method could effectively simulate the acoustic vibration environment caused by engine pulsation and aerodynamic noise to avoid product overtest. The purposes of evaluating the dynamic strength of the cabin structure and equipment and the dynamic characteristics and magnification of the equipment support were achieved.