In the micro-power wireless transmission of the electric system, positions among modes are relatively fixed, power business data is reported at specific time points, and time distribution presents great differences. Key technologies of IEEE802.15.4 MAC layer protocol is expounded, shortages of collision detection and CSMA/CA on power business support, etc. are discussed, self-adaptive low-power consumption CSMA/CA algorithm which is more suitable for business of the electric system are designed and improved, and the algorithm goes through simulation experiment against the business characteristics of micro-power wireless network of the electric system. The simulation result demonstrates the algorithm may be greatly adapted to changes of network traffic under a relatively fixed environment of network topology on the premise of low power consumption.