Pipeline cleaning method of surface cleaning device

The invention provides a pipeline cleaning method of a surface cleaning device, the pipeline cleaning method is applied to the surface cleaning device, and the surface cleaning device comprises a cleaning assembly, a dirt suction motor, a dirt containing barrel, a dirt suction opening and a dirt suction pipeline communicating the dirt containing barrel with the dirt suction opening; at least part of the dirt suction pipeline is a threaded pipeline with a threaded inner wall, and the pipeline cleaning method of the surface cleaning device comprises the steps that in the soaking cleaning stage, the dirt suction motor is controlled to operate at first power, and the first power changes within a first preset range or is kept at a first preset value; wherein the first power is smaller than the operation power of the sewage suction motor when the surface cleaning device executes the cleaning task, so that liquid flows moving in the sewage suction pipeline collide to form multiple strands of spiral liquid flows to s