The invention provides a preparation method of a powder accumulation structured all-metal active material. A coating cold rolling process is adopted to perform multi-pass continuous rolling on an active material blank, obtained through a powder molding method, to finally prepare the all-metal active material with higher energy release characteristics. The method can efficiently obtain massive all-metal active material. When the active material blank is further machined, a ladle is added to deform the active material blank with the powder accumulation structure under the constraint effect of three-way pressure stress, so that cracking caused by material brittleness in conventional deformation is prevented, the contact area among active components in unit volume is increased, and the combustion speed and the reaction efficiency of the active material are improved.