The invention discloses a pipeline pump abdominal cavity machining method and relates to the technical field of turbine machinery machining technique design. The pipeline pump abdominal cavity machining method is used for rapidly machining a pipeline pump abdominal cavity structure and comprises the steps that equal-height shim plates are arranged on a plano milling machine, and a pump body and apump cover are placed on the shim plates in the mode that the association planes are upward correspondingly; the pump body and the pump cover are compactly cushioned through the shim plates on the pressing plate clamping position and then clamped; the end faces of the pump body and the pump cover which are clamped are subjected to coarse machining through an end face milling tool program; the endface of an abdominal cavity of the pump body and an abdominal cavity spigot of the pump body are subjected to semi finish machining through a lengthened milling tool plate; and through a long millingtool plate, the abdominal cavity spigot of the pump body and the two end faces of the abdominal cavity are subjected to finish milling. By adopting the pipeline pump abdominal cavity machining method,overall machining of a pipeline pump product is developed into split machining, simple and rapid effects are achieved, the time and labor are saved, the blank of abdominal cavity split machining in the pump industry is filled up, a traditional machining mode is broken through, and the high popularization value is achieved.