A circuit structure for realizing circuit pin multiplexing, comprising an MCU module, a temperature sensing circuit and a functional module circuit. The output end of the temperature sensing circuit is connected with an enable signal interface of the MCU module, the output voltage of the temperature sensing circuit is always higher than the threshold voltage of the enable signal, and the MCU module is connected with the functional module circuit. The circuit structure of the present invention realizes the mutual influence of analog signal output and digital signal transmission by designing a temperature sensing output curve, and achieves multi-function multiplexing of a single pin, so that the output of the analog signal and the input of the digital signal can share the pins, it solves the problem of the limitation of the number of pins, and promotes the transmission of the signal and improves the cost performance of the circuit.