Interface level switch device

The invention discloses an interface level switch device. The interface level switch device is arranged on a main board and is used for detecting serial port signals and outputting level signals corresponding to a main board serial port controller of a serial port controller. The interface level switch device comprises a detecting module, a circuit switching module and an RS232 level conversion module, wherein the detecting module is used for detecting the serial port input signals so as to judge the type of the serial port input signals and outputs corresponding control signals according to judgment results; the circuit switching module comprises a logic control pin, an input end, a first group of output ends and a second groups of output ends, and the logical control pin receives the control signals sent by the detecting module and makes the input end selectively judge whether the serial port input signals are output from the first output ends or the second output ends; the RS232 level conversion module is connected with the first group of output ends of the circuit switching module and is used for converting RS232 serial port signals into CMOS signals and outputting the CMOS signals to the main board serial port controller.