Path planning is an obligatory method to improve aircraft’s survival probability. Modeling threat is a key issue in path planning. In order to satisfy the need of generating a specific path for aircraft rapidly, a reasonable description of threat sources in the operational space is necessary in the earlier stage of path planning. Based on fuzzy comprehensive evaluation method, a new solution to compute the threat degree of attacking aircraft is introduced. Finally the computable threat model was validated by a typical example after constructed. The result of the example shows that the threat model can support path planning preferably.