The invention discloses a water pump assembly high in airtightness. The water pump assembly comprises a base, a rubber gasket, a fixed frame, an impeller, a water outlet pipe, a solenoid valve, a protection shell, a motor, a mechanical sealing block, a handle, a support and a foam board. The rubber gasket is arranged at the bottom of the base, the top end of the base is connected with the fixed frame, the top end of the fixed frame is connected with the protection shell, and the top end of the protection shell is connected with the water outlet pipe. The outer side of the water outlet pipe issleeved with the solenoid valve, the impeller is arranged in the protection shell, a rotary shaft is inserted into the middle of the impeller, one end of the rotary shaft is connected with a motor, the top end of the motor is connected with the handle, and the support is arranged at the bottom end of the motor. The water pump assembly is scientific and reasonable in structure, safe and convenientto use, the rubber gasket is arranged at the bottom of the base, and shaking of a water pump body during work can be reduced; by arranging the solenoid valve, the water flow can be effectively controlled; by arranging the handle, a user can lift a water pump conveniently.