Automatic IP address searching method

The invention discloses an automatic IP address searching method, and relates to a technology in the field of communication, in particular to a communication method between an annunciator and an upper computer. The automatic IP address searching method is characterized in that by defining different ports, and monitoring the different ports by the annunciator and the upper computer, automatic search of the upper computer for the annunciator is achieved, and network connection between the upper computer and the annunciator is automatically established. The automatic IP address searching method has the benefits of high simplicity, reliability, wide application, and reduction in the failure rate of communication.