Abstract: In the stability design of a high-power laser facility, if equiprobable allocation results are chosen as the stability design indexes, there are often much difficulty in structure design and great waste in building. Thus, a stability reallocation way based on the finite element analysis (FEA) is put forward. That is, computing the linear weighted coefficients with the target orientation errors brought by the vibration responses of optical elements in a beam, and then reallocating the stability indexes by the linear weighted method. The safety factors are equal in the beam after the reallocation. Stability indexes in a beam of centain large laser facility’s target area are reallocated by this method, and all beams’ safety factors are 1.229, satisfying the requirement of stability design.