The invention discloses a terminal automatic registration method of the LPWAN Internet of Things, which is characterized in that it comprises the following steps: 1) assigning frequency points of working channels to the ISM frequency band; 2) selecting some channels as default channels to form a default channel group ; 3) The base station side of the network configures working channels, including at least one default channel; 4) When the terminal side registers, it randomly selects one of the default channel groups to send a registration message, and can repeat it multiple times if it fails; 5) The network side receives After receiving the registration message of the terminal, the terminal is authenticated, and if successful, a registration acceptance message is returned to the terminal, carrying the indication of the working channel; 6) The terminal receives the registration acceptance message and obtains all working channels on the base station side. Beneficial effects achieved by the present invention: the method has made great progress, achieved the effect of fast terminal registration, saved power consumption in the terminal registration process, solved the problem of mutual interference when multiple networks coexist, and improved the network working channel notification efficiency.