The utility model relates to a continuous wax injection device. The continuous wax injection device mainly comprises a dewaxing tank, a pressure tank, a tee valve and a spraying gun. An air inlet of the tee valve is communicated with an air source; a first air outlet of the tee valve is connected with a dewaxing air inlet located at the upper end of the dewaxing tank through a pipeline; a second air outlet of the tee valve is connected with a pressure air inlet located at the upper end of the pressure tank through another pipeline; the dewaxing tank is connected with the pressure tank through a wax conveying pipe; a pneumatic connection valve is arranged on the wax conveying pipe; the lower end of the dewaxing tank and the lower end of the pressure tank are respectively provided with a quartz heater, the quartz heater at the lower end of the pressure tank is provided with a through hole communicated with the inner portion of the pressure tank; the through hole is connected with the spraying gun through a wax outlet pipe; the wax outlet pipe is provided with a hand-operated ball valve. Because working procedures such as the charging procedure, the dewaxing procedure and the filling procedure are continuous, working efficiency is improved, construction quality is guaranteed, working time of operation personnel in the environment with trace irradiation is shortened, and the safety coefficient is increased.