The pump integrates self-priming and non-clogging sewage discharge, adopts the axial return and external mixing type, and through the unique design of the pump body and the impeller flow channel, it does not need to install the bottom valve and irrigation water like the general self-priming clean water pump. It can also suck and discharge liquids containing large particles of solids and long fibers. It can be widely used in municipal sewage projects, river and pond aquaculture, light industry, papermaking, textiles, food, chemicals, electricity, fibers, pulp and mixed suspension. The ideal impurity pump.