In order to study the aerodynamic characteristics of the model under high angle of attack ventilation, a special ventilation force measurement wind tunnel test device was developed. The device consists of a sixcomponent balance, two bellows and other parts. The bellows realize the ventilation and air tightness requirements of the model, and the balance realizes the force measurement requirements of the model. ANSYS software is used to simulate and analyze the characteristics of the balance and bellows. The detailed structure and theoretical results of bellows interference on the balance are obtained. The working formulas of the balance and the force measuring device are obtained by static calibration. The results show that the finite element analysis is consistent with the measured results. The measurement accuracy of the force measuring device is further verified by wind tunnel test. The results show that the force measuring device meets the design requirements and meets the requirements of this type of wind tunnel test.