Steam pipeline air leakage detecting device

The invention relates to a steam pipeline air leakage detecting device. The problem that an existing pipeline connector lacks of an on-line detecting device is effectively solved. According to the technical scheme for solving the problem, the steam pipeline air leakage detecting device comprises a circular pipe, a first piston cavity is formed in the side wall of the circular pipe, a first pistonis mounted in the first piston cavity, the first piston cavity is provided with a first exhaust hole and an elastic block, a second piston cavity is formed in the lower surface of the first piston, asecond piston is mounted in the second piston cavity, a vent hole communicating with the second piston cavity is formed in the first piston, a vertical first vent groove is formed in the inner wall ofthe first piston cavity, the vent hole communicates with the first vent groove, a first exhaust channel is formed in the second piston, a vertical second vent groove is formed in the inner wall of the second piston cavity, a s