The cause that the misfiring rate of fail-safe in the sub-munition fuze of the cargo projectile is abnormally high is analyzed

and the method by adding pre-torsional moment of the torsion spring and adjusting the mass center of the rotor is adopted to optimize the rotor of the sub-munition fuze

which based on quality characteristic and measuring tool to create SolidWorks modeling program.Through the shooting range experimentation

the misfiring rate of fail-safe is decreased to below 2% distinctly

and it can fulfill the tactical and technical index.