Abstract:In a certain type of underwater weapons electromagnetic fuze test on land, aiming at the demand that a massive iron plate should be accelerated to a high speed in a short distance, a method of iron plate vehicle hydraulic catapult was presented.The hydraulic system design ideas, hydraulic system work principle were elaborated.The research result has been applied to practical, good effect has gotten. While it also provides good design ideas for other highspeed ejection system.