The invention relates to a vacuum test device and method for leakproofness detection of a patrol bomb launch canister. The leakproofness qualification of the launch canister is judged by putting the launch canister into a vacuum test cavity, vacuumizing and observing the pressure drop of a vacuum gauge. The device is formed by sequentially connecting an
exhaust valve, a vacuum test cavity (including a vacuum meter), a control valve, a pneumatic pipeline, a pneumatic flow regulating valve, a switching valve, a vacuum
buffer tank (including a stop valve) and a
vacuum pump according to the air exhaust direction. During vacuumizing, the
vacuum pump is started to vacuumize the vacuum
buffer tank, after a certain vacuum degree is achieved, the
buffer tank serves as a vacuum generator to vacuumize the vacuum test cavity, the air exhaust rate is adjusted and set through the pneumatic flow adjusting valve, and opening and closing control over an
air channel is achieved through the control valve. The vacuum buffer tank serves as a vacuum generator, frequent starting and stopping of a
vacuum pump are avoided, and the service life of equipment is prolonged; the
test requirements of multiple products can be met through one-time evacuation, and the
test efficiency is improved; the air exhaust rate is stable and adjustable, and the consistency of product test states is ensured.