The output of electric detonator charged with hexanitrohexaazaisowurtzitane (HNIW) was measured on the basis of GJB5309.1~.38: steel dent test method, the output increased over 10% and the minimum quantity of initiation explosive decreased compared with HMX. The results show that HNIW is an optional explosive for miniaturization of detonator in condition of the coequal initiation power.