To rationally optimize the location of logistics distribution centers, the related characteristics and ap- plication of Voronoi diagram were introduced to realize the dynamic division of the logistics node service range. Considering the influencing factors which affect the logistics node location, and giving the corresponding weight value, this paper established the improved P-median model, and built up the objective function with the mini- mum total service cost. Combining Voronoi diagram with the improved P-median model, based on dynamic ser- vice range division of the logistics node in the Voronoi diagram, the optimization algorithm of the model with Matlab programming was used to solve the optimal node location layout of the whole logistics system through continuous iteration. The research results show that the optimization method of logistics node based on Voronoi diagram is reasonable, which can make the total distribution cost minimum, reduce the logistics cost and improve the logistics efficiency.