The invention discloses an explosive recrystallization preparation method and a device for explosive crystallization. An explosive stock solution is poured into a grille crystallizing pan, and then the grille crystallizing pan is placed in a precise constant-temperature heating water tank, heated to 59-61 DEG C and kept at the constant temperature; a top-end air suction system is started, and the air suction speed is stabilized at 0.73-0.77 m/s, so that all explosives are crystallized. The device for explosive crystallization comprises the precise constant-temperature heating water tank, the grille crystallizing pan and the top-end air suction system, wherein the grille crystallizing pan is placed in constant-temperature water in the precise constant-temperature heating water tank, so that the periphery and the bottom of the grille crystallizing pan can be heated by the constant-temperature water, the top-end air suction system is arranged right above the grille crystallizing pan, and a grille of the grille crystallizing pan is arranged on the inner bottom surface of the grille crystallizing pan. The method and the device have a function of precisely controlling the temperature and the volatilization speed of the recrystallized stock solution, the initiation sensitivity of prepared explosives is obviously improved, the shock sensitivity is greatly reduced, and the production efficiency is substantially improved.