The invention belongs to a test result-based finite element model modal adjusting method, and specifically relates to a carrier rocket modal test result-based finite element model modal adjusting method. According to the method, the adjustment of the modal of a finite element three-dimensional model is realized through automatically adjusting the key parameters which influence the rigidity of the finite element model by taking a carrier rocket modal test result as basis. The method has the following advantages in two aspects: (1) automation: after extracting the key parameters which influence the modal of the finite element model, the modal of the finite element three-dimensional model is optimized and adjusted through an optimization algorithm so as to ensure that the modal of the finite element three-dimensional model agrees with the modal test result; and (2) high efficiency: through the method, the optimization algorithm is combined with a modal calculation method, so that the modal of the finite element three-dimensional model can be adjusted in a relatively short time. The method has the characteristic of openness and has high engineering application value.