A new threat assessment method for Beyond-Visual-Range(BVR) air combat is proposed taking capability threat, situation threat and intention threat into consideration.Firstly, the first-shot capability threat model and the attack threat model of the BVR air-to-air missile are added to the capability threat model.Secondly, the situation threat is modified by the situation validation factor and the missile-guidance validation factor.A new situation threat calculation method is given.Then, the target maneuvering recognition and situation prediction are carried out based on the Hidden Markov Model (HMM) and then an intention threat modeling method is proposed.At last, a simulation is carried out on the comprehensive threat assessment model, which proves that the proposed method is effective in BVR air combat.