The invention discloses a data communication method of a wireless sensor network, which can solve the problems of the traditional cluster routing protocol that the energy consumption of the cluster head is high, and the network bottleneck can be easily formed, thereby making the energy consumption of nodes uneven and shortening the network lifetime. The data communication method comprises the following steps: providing a wireless sensor network topology; designing a method for establishing clusters in a network clustering process; defining gateway nodes used for receiving and transmitting data between adjacent clusters; designing a data transmission routing process, wherein a cluster head node is only responsible for finding a data transmission path, and actual data are transmitted along the found path through the gateway nodes, thereby realizing the separation of path finding and data transmission and reducing the load of the cluster head node; and designing an in-cluster routing method used for transmitting the data to a designated gateway node. The data communication method designed in the invention can effectively reduce the energy consumption, balance the network load, and prolong the lifetime of the network. Therefore, the data communication method is applicable to large-scale wireless sensor networks.