Abstract: To solve the problem of UAV path planning across weather threat, the harsh weather zone occurring during UAV s trip was discussed adequately and abstracted into mathematical model. An additional control force was introduced into artificial potential field method as the optimization variable for path planning. The artificial potential fields were built up in terms of a generalized form describing spatial constraints, i.e., the probability of accomplishment of the task, which could release the rigorous requirements on field s foundation. Simulation results verified that the proposed method benefits to UAV path planning across weather threat. At the same time, the proposed method inherits the advantages of traditional artificial potential field method, and improves the disadvantages that the trajectory is apt to sink into local minimum and the foundation of potential fields lacks of actual significance.