In the existing directional sensor networks, the centroid point of node model usually rotates around the sector vertex. The node rotation area is a full circle; therefore the networks energy consumption and deployment time are multiplied. This paper presents a new node model, the sector node rotates around the centroid, the rotating area of the node is declined and therefore the deployment is optimized. Based on this model, we present Potential Field based Priority Coverage Algorithm (PFPCA) for node deployment, and finally make simulation for this algorithm to explore the parameters which affect the coverage probability. The simulation results show the effectiveness of the model and algorithm. Copyright © 2014 American Scientific Publishers.