The invention belongs to the technical field of industrial electric furnaces, in particular to a method for monitoring a temperature curve of a tunnel furnace. The method comprises the following steps: the temperature sensing part of a thermocouple for monitoring is fixed to the portal of a conveyer belt, and two signal wires are connected to a monitoring temperature controller; the communication port of the monitoring temperature controller is matched and connected with the RS232 port of a PC through a PS232/RS232 converter, and while the conveyer belt operates, a temperature curve monitoring program in the PC is started; and in the operation process of the conveyer belt, the thermocouple for monitoring senses a temperature signal in each time period together with a workpiece and transmits the temperature signals to the monitoring temperature controller, the monitoring temperature controller transmits the temperature signals to the PC through the communication port, and the PC displays the temperature in the current time period in real time and draws a real-time temperature curve. The method can directly display an actual temperature curve sensed by the workpiece in the heat treatment process in real time, discover abnormal conditions at any time, and call, retrieve and print history data at any time, thereby providing reliable references for technologists in heat treatment process.