Based on the basic theory of Genetic Algorithm and fiber Bragg grating sensing with transverse uniform press, an analytical method of Genetic Algorithm in quasi-static fiber grating sensing system with transverse uniform press is proposed and the relevant mathematical model is established. The objective function related with Genetic Algorithm is also established. The effect of population size, generations, crossover ratio and mutation ratio to Genetic Algorithm is studied, and the optimization parameters of Genetic Algorithm are given. Meanwhile, the relevant experimental system is constructed, and the related simulation and experiments are finished. The simulation and experiments show that the analytical method proposed can be applied to quasi-static fiber grating sensing system with transverse uniform press, and the accuracy can achieve to 0.91%.