For correcting the erroneous dropping of external stores on dropping mechanism of aeronautical weapons,a finite element technique was adopted to analyze on the hook,sector rocker and sector wheel to find out the reasons for erroneus dropping,and an improvement method was put forward without changing the structure of the dropping device.A mechanism applicable in micro space was designed with computer-aided 3-dimension motion analysis and interferometry.By using computer-aided statics,dynamics,thermo-elasticity and stability engineering analysis(CAE) techniques, the structural stability of the mechanism was studied in aspects of dropping sequence,energy requirements,rigidity and the intensity of stop. The results of calculation,experiment and aerial embarkation flight show that the theoretical power value consumed by the stop is 10 W,and measured value is 14 W;the measured value of tripping voltage is 7 V,and the theoretical value of the time sequence is 0.003 8 s,these values are much less than those of the dropping device itself.Experimental results show that improved mechanism acts safely and reliably,and avoids mutual interference between all moving accessories of the main body,which provides evidence for engineering application.