To address the problem in reconnoitering the field communication network, a UAV path planning method is put forward for a full-coverage search of the deployment area of the field communication network by using crossed paths. Firstly, according to the structural characteristics of the field communication network and the node antenna beam, the maximum reconnaissance distance and the blind reconnaissance distance of UAV reconnoitering the nodes are obtained through a qualitative analysis. Then the static model and the dynamic model of UAV reconnoitering the nodes are obtained as well. Then, based on the reconnoitering model, the UAV crossed searching path model with exhaustive searching abilities is built and optimized. This method can find out all the nodes of the field communication network and improve the search efficiency. Lastly, a simulation of UAV crossed searching path is carried out. The simulation results indicate that the method can find out all the nodes of the field communication network, and the cost of UAV crossed searching path is calculated.