The optimization of the location of precast components is an important method of cost control in the optimal design of prefabricated shear wall structures. With the selection of precast components determined, the location of precast wall-beam combined components is optimized by combining immune genetic algorithm, the minimum precast component volume is the objective function, the structural torsional displacement ratio and story drifts are the constraints. The optimization results of the algorithm show that the optimized location of the precast components combined with the immune genetic algorithm can satisfy the structural constraints, the volume of the precast components is smaller and the optimization is more economical.