The invention discloses a constant-temperature flusher which comprises a shell, a spray gun seat, a peristaltic pump, a heating ring, a digital temperature sensor, an infrared sensor, an exhaust fan, a circulating fan, a touch screen, a main control board, a filtering socket, a grounding pole, a switching power supply, a button switch, a temperature switch, a proximity switch, a pushing structure cover and a spray gun. The peristaltic pump, the main control board and the switching power supply are installed at the bottom in the shell, the heating ring is installed in the middle in the shell, the infrared sensor is installed at the bottom of the heating ring, and the digital temperature sensor and the temperature switch are installed on the inner wall of the heating ring; the temperature is always kept in the preset target temperature interval, continuous operation is facilitated, and the situation that excessive energy is scattered to pay attention to various objective conditions of equipment in the operation and even continuous operation is affected is avoided.