Aiming at the problem of output fluid pulsation of multiple hydraulic cylinders of hydraulic fracturing pump, the pulsation mechanism of hydraulic fracturing pump was analyzed. On this basis, a pulsation suppression method for hydraulic fracturing pump based on displacement coordinated control was proposed. And the simulation model was established according to the prototype parameters. And the correctness of the simulation model was verified under the working condition of 55 MPa output pressure. And the simulation was carried out under the conditions of maximum engine output power and maximum fracturing pump output flow. The theory and simulation results show that the pulsation suppression method for hydraulic fracturing pump based on displacement coordinated control, by detecting the displacement of the plunger in each hydraulic cylinder in real time, the signal that the plunger of one cylinder is about to be in place not only controls its own deceleration and stop, but also controls the start and acceleration of the plunger of the other cylinder, so that the deceleration and acceleration processes of the plunger of the two cylinders overlap each other. Using this method, the forced and orderly reversing of the hydraulic cylinder plunger is realized,the flow and pressure pulsation can be significantly suppressed. Under the condition of maximum engine output power and maximum fracturing pump output flow, the output flow pulsation of hydraulic fracturing pump is reduced from 25.45% to 11.55%, and the output pressure pulsation is reduced from 46.58% to 21.93%.