Fixed-wing Unmanned Aerial Vehicle （UAV） is widely used in reconnaissance missions because of its high speed， low cost and ability to carry more equipment. In this paper， path planning for cooperative patrol coverage of fixed wing UAV in complex mountain environment is studied. Different from previous studies that focus on using UAV to achieve complete coverage of the whole area， the focus of this paper is on multiple UAVs’ collaborative patrol of the mission area to ensure that all locations in the area can be continuously visited by UAVs. In previous studies， the cooperative mode of UAVs is to cover each subarea separately， while in this study， multiple UAVs work cooperatively in the whole area， so as to deal with emergencies more flexibly on the basis of improving coverage efficiency. To meet the need to visit the target area in a short time in emergency situations， a strategy of dynamic target points and a small-scale crossing coverage algorithm are designed to ensure that the UAV selected for emergency tasks can reach the target area within a specified time while keep the efficiency of normal patrol task， and can also achieve complete coverage of the target area. Finally， simulations are carried out to verify the feasibility and optimization effect of the algorithm proposed in the reconnaissance coverage task. The superiority of the dynamic target point strategy over static target point strategy is also verified in the urgent task.