Recent advancement in wireless communications and electronics has enabled the development and application of low-cost, energy efficient and multi-function wireless sensor network (WSN). Coverage optimization is a fundamental issue for the operation and management of Wireless Sensor Network, which is aimed to obtain long system lifetime, as well as maintain sufficient surveillance to targets.Scheduling the redundant nodes to sleep alternately can prolong the network lifetime efficiently. In this paper, the node scheduling scheme of a kind of random sensor networks is studied. Based on a large number of literatures on the sleep algorithm of wireless sensor network, kinds of the current sleep algorithm based on redundant node determine are analyzed and acquired. However, the following problems exist in these kinds of redundant node determine algorithms. Firstly, the complexity is too high.Secondly, too many work nodes are picked. Besides, the boundary nodes are not able to sleep. To solve these problems, based on the Tian D arithmetic on the sector coverage, this paper designed an improving wireless sensor network sleep mechanism with the reference of circle coverage thought of Huang arithmetic. This method firstly uses the density control to sleep part of the nodes in the region of over high redundancy ratio in order to make the active nodes distribute more equally.
