The invention relates to a module with a short circuit protection function for a serial port and a method. The module comprises a DB9 male socket, a 9-core insert needle and a short circuit protection circuit, wherein the 9-core insert needle is connected with a main board and is used for receiving a serial port signal from the main board; a signal wire of the DB9 male socket is connected with the 9-core insert needle and is used for outputting a processed serial port signal; and a power line of the main board is connected with an external device through the 9-core insert needle, the short circuit protection circuit and the DB9 male socket. According to the invention, the normal work of a main engine still can be guaranteed even if the power supply is short-circuited in the process of frequently plugging and inserting in an electrified state.