Serial port communication method, device and system

The invention discloses a serial port communication method, device and system. The method comprises the following steps: sending handshake establishment information to opposite-end equipment, so that the opposite-end equipment writes handshake protocol content into a serial port buffer area of a target serial port after receiving preset delay time of the handshake establishment information; within preset delay time, emptying a serial port buffer area of a target serial port in the opposite-end equipment in a mode of discarding the read data; and if the serial port buffer area is emptied, executing the handshake protocol model to receive handshake protocol content sent by the opposite-end equipment through the serial port buffer area. The technical scheme has the beneficial effects that the serial port buffer area of the target serial port in the opposite-end equipment is emptied in a mode of discarding after reading data, and the delay time is set to ensure that the serial port buffer area is emptied when han