The linear conjugate internal gear pump is widely used in the electro-hydraulic actuator (EHA) system because of its high efficiency and low noise,especially in the ship domain that vibration and noise requirements are very strict.To find out the reason,the calculation method of flow fluctuation and pressure pulsation at the pump outlet was obtained theoretically, that was,the method obtaining pump source flow pulsation Qs and pump source impedance Zs. Meantime, the data calculation and processing program was compiled by MATLAB.Then the test platform was built,the data were collected. According to the theoretical method,the actual flow fluctuation and pressure pulsation at the pump outlet under different working conditions were measured and calculated respectively. The data of each working condition are summarized and analyzed: the test platform is reasonable,the data obtained from the test and calculation are reasonable;under the same frequency spectrum,the amplitude corresponding to the fundamental frequency of the motor pump is much larger than that of the pump tooth;under different working conditions,the variation trends of flow fluctuation and pressure pulsation corresponding to the fundamental frequency and the frequency multiplication of internal gear pump are obtained by testing,the specific values are smaller,suitable for use in silent system.