The invention discloses a constant-temperature heating system for heating the keyboards of electronic apparatuses, comprising a power supply, a control circuit, a heating device and a feedback circuit, wherein the control circuit is electrically connected with the power supply; the heating device is electrically connected with the control circuit; and the feedback circuit is electrically connected with the control circuit and comprises a temperature sensing device which is electrically connected with the feedback circuit and connected with the heating device through a temperature sensing lead. The constant-temperature heating system provided by the invention can precisely control the temperature in a predetermined temperature, and is stable and not easy to be damaged.