Fuente: Wipo "IOT" The invention provides an NB-IoT network resource allocation method, terminal, device and system, and relates to the technical field of the Internet of Things. The NB-IoT network resource allocation method disclosed in the invention comprises the steps that an NB-IoT terminal determines a coverage enhancement level according to narrowband reference signal receiving power; when the NB-IoT is initially accessed, a coverage enhancement level is reported to an NB-IoT base station, so that the NB-IoT base station determines the retransmission times and/or modulation and coding strategy of the downlink channel according to the coverage enhancement level. By means of such a method, the NB-IoT terminal can determine the coverage enhancement level and send the coverage enhancement level to the NB-IoT base station. And the NB-IoT base station adjusts the retransmission times and modulation and coding strategies of the downlink channel according to the reported information; self-adaptive adjustment of the base station is realized according to the detection condition of the NB-IoT terminal, the success rate of data transmission is improved, data transmission time delay is reduced and system capacity is improved.