This paper proposes a new path planning algorithm based on the CNN model. The path planning problem is completed with the dynamics of CNN by establishing a relationship between path control points and CNN cells. Based on the analysis of one dimensional space of CNN algorithm, a CNN equation is constructed and the path updating algorithm under the curvature constraint is obtained, then the stability of the algorithm is discussed. Path planning simulation based on two-dimensional space shows that this algorithm can avoid re-planning or falling into the local minimum, which means it can be successfully used in the path planning and maintenance of robots on the ground in dynamic environment.