The invention discloses a toy water gun. The toy water gun comprises a front shell and a rear shell which are hermetically and fixedly connected, wherein a round piston rod hole is formed in the upper part of the front side of a front handle part, and a water inlet part is formed in the inner wall at the rear end of a rear handle part corresponding to the position of the piston rod hole; the water inlet part comprises a spring positioning part and a round tubular water inlet casing, and water inlets are uniformly formed in the front part of the water inlet casing along the axial direction; an elastic rubber or plastic pump body is arranged between the piston rod hole and the water inlet part, and the pump body comprises a slide rod part and a corrugated pipe part which are integrally molded; a water outlet connector and a spring positioning ring are formed in the side wall of the pump body; the water outlet connector is connected with a water outlet pipe, and the other end of the water outlet pipe is connected with a nozzle; the slide rod part penetrates through the piston rod hole from inside to outside, and is in hermetical sliding connection with the piston rod hole; the rear end of the corrugated pipe part is arranged on the water inlet casing in a slide sleeving manner; and a spring is arranged outside the corrugated pipe part and positioned between the spring positioning ring and the spring positioning part in a sleeving manner. The toy water gun has the advantages of few parts, convenience in assembly and low labor cost.