In wireless sensor networks

three-dimensional（3D） localization plays a crucial role in applications of fire preventing

target tracking

disaster warning

and environmental monitoring

and so on.Research on valley terrain DV-Hop localization algorithm for wireless sensor networks.Through analysis on 3D DV-Hop algorithm error

the main reason for the deviation is pointed out

improved algorithm is presented.Simulation results show that the improved algorithm enhances the nodes localization precision.The suitable proportion of anchors with 3D DV-Hop localization algorithm based on valley for wireless sensor networks is pointed out.