According to the application of wireless sensor networks in three dimensions,a novel 3D positioning algorithm based on Euclidean for wireless sensor networks is proposed.The problem of the distance calculation between an unknown node and an anchor node is transformed into a solution of the distance between the vertices in Hexahedral.It can be realized by the method of coordinates.The coverage is increased by the way of cyclic iterative method.Simulation results indicate that the performance of the algorithm is good and the algorithm can effectively realize the position of nodes for wireless sensor networks in three dimensions.