The invention discloses a quick-opening valve for an explosion suppressor. The quick-opening valve comprises a valve body, a piston and a valve rod, wherein the front section of the valve rod is fixed on the piston, and the rear section of the valve rod is fixed in an explosion suppressant inlet; a closed gas generation cavity is formed in the bottom of an inner cavity of the valve body; a trigger is arranged on the piston; and a tensile rupture band is arranged on the rear section of the valve rod, under the condition that the piston is pushed by high pressure gases in the gas generation cavity, the tensile rupture band is pulled apart, and meanwhile, the explosion suppressant inlet is communicated with an explosion suppressant outlet. According to the quick-opening valve for the explosion suppressor, when the trigger triggers a gas generating agent, the high pressure gases push the piston to move, so that the tensile rupture band is stressed and ruptured, the explosion suppressant inlet is communicated with the explosion suppressant outlet, an explosion suppressant is sprayed quickly, and the response time is short; meanwhile, if the rod diameter of the valve rod is increased, the explosion suppressant inlet can be enlarged correspondingly, so that the spraying speed is increased, and the explosion suppression effect is improved; and the high pressure gases in the gas generation cavity are sealed and isolated from the outside, so that the outside environment is not affected, and the safety performance is guaranteed.