The invention provides a MAC layer realizing method of a clustering structure wireless sensor network, and the wireless sensor network using the realizing method. The realizing method comprises four steps, which are cluster frequency choosing, initial time slot division, sleeping or data sending, and time slot adjustment. Specifically, when the frequency of a cluster-head announcement sent by a cluster-head node collides with the cluster-head frequency of another cluster, the other cluster-head is required to carry out frequency adjustment; the initial time slot division is carried out according to the remaining energy of each member node in the cluster; a wireless module is put to sleep or waken up according to whether data sending is required, and control information is sent before and after sending data; in the following frames, the time slots of the current frame are adjusted dynamically according to the busy degree of the previous frame. In the invention, the overall energy consumption of the wireless sensor network is lowered, and the average transmission delay of data packets is reduced.