In order to obtain the influence of initiation mode on power field of cloud detonation, the TNT charge was applied to throwing clouds for asymmetric single point initiation. Through cloud detonation process and overpressure values of different distances and directions got by high speed camera and pressure sensor, the propagation characteristics of cloud detonation wave and the variation law of overpressure with distance and direction were analyzed. The results show that with asymmetric single point initiation, clouds inside overpressure distribution show obvious uneven, part of the region takes on superimposed effect of shock wave, and with increase of the distance, overpressure distribution tends to be uniform, detonating manner on cloud detonation power field effect is mainly reflected in the near field.