The invention relates to the technical field of cam pump with large flow and large power, particularly relates to a cam rotor pump with large power and low pulsation. The cam rotor pump is characterized by comprising two same rotors arranged in a cavity, the rotors are circumferentially and fixedly arranged on a rotary shaft through key groove, the rotors are axially fixed on the rotary shaft through a locking nut and a locking block, the side surface of the cavity is provided with a pump cover corresponding to the rotor; a 0 to 0.2 mm gap is formed between the rotor and the cavity, the rotaryshaft is fixed on a gearbox through a double-row tapered roller bearing and a cylindrical roller bearing, the two rotary shaft rotates at same rotary speed through the engaging between two synchromesh gears, a 0.4 mm gap is formed between two rotors, the side surface of the gearbox is provided a gearbox cover, a mechanical sealing mechanism is arranged on the connection part of the rotary shaft and the cavity, a rubber oil sealing is arranged on the connection part of the rotary shaft and the gearbox cover. According to the cam rotor pump, the operation of equipment is stable, a transition line is adopted for a chamber-wall line, the flowing of a flow in the pump is optimized, the pulsation phenomenon of the flow is greatly reduced,and the noise of vibration is reduced.