The utility model discloses a pneumatic frock, include: a pedestal. The cylinder, the cylinder body of cylinder is fixed in on the base, two at least installation departments, installation department are fixed in the base, and every installation department corresponds the work piece in location, and the piston rod in the cylinder cooperates the tight work piece of clamp with all installation departments simultaneously. This kind of pneumatic frock only needs place the work piece in the installation department when using, then the action of control cylinder presss from both sides when once can realize at least two work pieces tightly, can reduce the tool replacing times in clamping number of times and the course of working, reduces staff's intensity of labour, puies forward high pressure heater work efficiency rate.