Abstract: Due to the energy of WSN node is so limited, sharing the channel fairly for every node can extend network life. On the basis of theoretical analysis, the structure of IEEE 802.15.4 superframe was redesigned for lack of the current superframe. In order to reduce the conflicting probability among nodes, sub-area competition and slotted scheduling were involved, and feature parameters to measure the network fairness index were put forward. Experimental results indicated that the proposed method effectively solved the problem of unfair channel contention under traditional CSMA/CA mechanism and reduced the max backoff times and cache occupancy rate, which balanced the distribution of network energy to extend the network life.