The invention relates to an allowance research method of a hydraulic pump. The allowance research method includes the following specific steps that statistics is conducted on the out-of-tolerance condition of a component which is used in the current state, and repairing experience data are obtained; the reason for generating the out-of-tolerance condition at all positions of the component is triedto be analyzed from the angle of theory, and whether certain out-of-tolerance data can meet the performance requirement of an oil pump or not is proofed; specific implementation is conducted according to an earlier stage, and test results are obtained; and argument and analysis are conducted on the test result, the repairing tolerance is determined, and repairing technical standards are formed. By means of the allowance research method of the hydraulic pump, statistics and analysis are conducted on the out-of-tolerance condition of the part, a theoretical model is established, and the tolerance indicator is determined; a test technical scheme is formulated with the combined with related specifications according to project indicators, and tests such as a durance test, a pressure pulsationtest and a starting-stalling circulation test are conducted on an out-of-tolerance test sample; and the research result is verified according to test results, the repairing tolerance is determined, and a repairing technical standard is formed. The purposes of reducing repairing cost and ensuring the repairing period are achieved.