The invention belongs to the mechanical production field and relates to a detection fixture device used for detecting sealing of a welding part. The device comprises a detection component, a welding component, a cylinder 1, a cylinder installing plate, a nut, a rotation handle, a rotation cylinder installing plate, a cylinder 2, a baffle plate, a rotation block, a right support, a rotation shaft, a left support, a bolt, a fixing platform, a lower platform plate, a stand column, a part placing platform, a connection pole 1, a connection pole 2, a spring, a limiting bolt, a rotation plate, a linear slide rail, a cylinder 3, a mark pin, an air hole, a connection rod and rubber plugs. The detection component is placed at a detection fixture platform position. The rubber plugs connected to the cylinders rapidly plug a part measurement portion. Through the air holes on the connection poles, a constant value pressure gas is conveyed to the measurement portion and a pressure gauge change value is checked. If the pressure value does not change, leakage does not generated on the measurement portion, and then the qualified part is marked. A whole measurement process is rapid and accurate. Detection efficiency is increased and an error measurement rate is reduced.