The invention provides a short-distance cover system. When an access point device is in communication with a terminal device, channel quality is detected on the access point device through a feedback mechanism and a verification mechanism, a physical layer instruction is sent, the terminal device is controlled, and the order of a modulation system is adjusted at the same time, so that the modulation system is adjusted in an adaptive mode according to the channel quality. When the channel quality is good, a high-order modulation system is used, spectrum efficiency is improved, the transmission rate is improved, and transmission time delay is reduced; when the channel quality is poor, a low-order modulation system is used, and communication transmission reliability and stability are improved. The invention further provides an electric power TD-LTE wireless dedicated communication system. On the basis of the application of the short-distance cover system, the indoor cover capability of an LTE network is improved, a blind area and a shadow area of communication are eliminated, the communication spectrum efficiency is improved, the transmission rate is improved, the transmission time delay is reduced, and communication transmission reliability and stability are improved.