To meet the actual requirements and maximize economy and efficiency, the size of heliostats is designed, and efficiency optimization is achieved through a reasonable layout. In this study, linear and nonlinear programming models are constructed. With the objective function of minimizing the shadow occlusion between heliostats, the optimal size and height of heliostats and the shadow length are obtained. Combining the circular layout strategy of radial staggered radiation grids and the simulated annealing algorithm, with the annual average thermal power output per unit mirror area as the optimization target, the target of a rated power of 60 MW is achieved. The research results show that the annual average optical efficiency of the optimized heliostat field is 29.91%, and the average yearly thermal power output per unit area is 341.78 kW/m², providing an important basis for the design and construction of solar thermal power plants.