Test point selection is the premise of fault diagnosis.Analysis was made to the relation between signal and fault mode,on which basis,the systematic relationship model of weapon-launching control channel and the correlation matrix were founded.By using the heuristic function established for measuring the virtues or defect degree of the test sets,a heuristic optimal test scheme was designed.Then genetic algorithm was used to deal with correlation matrix,and the optimal test point set was obtained.Simulation results show that the scheme can effectively improve the efficiency of the fault diagnosis for weapon-launching control channel in a certain plane.