The utility model discloses an initial rainwater discarding processing system of rain and sewage flow converging water pipe, shift the equalizing basin including one, the intercommunication has rain and sewage flow converging water inlet tube, later stage rainwater discharging pipe and initial stage rainwater tank to shift the pipe on shifting the equalizing basin, later stage rainwater discharging pipe connects the urban rainwater pipe network, an initial stage rainwater tank, initial stage rainwater tank includes equalizing basin and the valve pond that communicates with the equalizing basin, equalizing basin one side is passed through initial stage rainwater tank with the transfer equalizing basin and is shifted the pipe intercommunication, be equipped with the transfer mouth with equalizing basin looks adaptation in the valve pond, shift mouthful corresponding one -level stop valve that is provided with, it shifts the mouth to be equipped with the pump on the valve pond, a catch basin, the drain of catch basin and valve pond intercommunication, the valve pond is equipped with the second grade stop valve at the drain, catch basin one side intercommunication sewage pipe network, the utility model has the advantages of reasonable design simply, can reach the automation and abandon class purpose of initial stage rainwater, whole system does not need manual control, the resource of using manpower sparingly.