Construction method for newly-added pretreatment equipment without reducing production of sewage treatment plant

The invention provides a construction method of newly-added pretreatment equipment without production reduction for a sewage treatment plant, and belongs to the field of sewage treatment. The method comprises the steps of assembling a temporary overrunning system, and assembling an intercepting device, a water pumping device and a flow guide device; installing the temporary overrunning system, installing the intercepting device at the upstream of sewage plant pretreatment equipment to be built or upgraded and transformed, and intercepting sewage; using the water pumping device for pumping the intercepted sewage and conveying the sewage to a next process of the sewage plant pretreatment equipment to be built or upgraded and transformed through the flow guide device; building or upgrading the sewage plant pretreatment equipment; and removing the temporary overrunning system, and removing the intercepting device, the water pumping device and the flow guide device. When the sewage plant pretreatment equipment is