The impeller was installed to the special type of sewage pump that is submersible sewage pump, and with B-level precision open test bench on the type of test, the main test results: the use of closed-blade impeller pump fully meet the GB3216- 92, GB / T13007-91, JB5118-91 and other standards, the use of flow-type impeller pump also fully meet the CJ / T3038-1995 standard requirements, so the product fully qualified. The H-Q curve of the closed-blade impeller is relatively flat, while the P-Q curve increases rapidly with the increase of the flow rate, and the slope is large, so it is prone to overload.