Shield tunneling machine foam pipeline dredging device

A foam pipeline dredging device of a shield tunneling machine comprises a propulsion pump and an energy storage dredging unit, the propulsion pump is used for providing hydraulic oil for the energy storage dredging unit, and the energy storage dredging unit is connected with a foam pipeline on a soil bin of the shield tunneling machine; the energy storage dredging unit comprises a three-position three-way electromagnetic directional valve, a first valve, an energy accumulator, an overflow valve and an overflow oil tank, and the first valve and the three-position three-way electromagnetic directional valve are arranged on a pressure oil way between the energy accumulator and the boost pump; the overflow valve is arranged on the overflow pipeline between the energy accumulator and the overflow oil tank, and one oil outlet of the three-position three-way electromagnetic directional valve is connected with the foam pipeline through a dredging oil pipe. Hydraulic oil is pressurized and released through the energy