In this paper, the optimization model of the annual average thermal power output per unit area is first established. Then the correlation analysis of the optimization parameters is carried out to obtain the conclusion that the sizing of the heliostat can determine the other optimization parameters, and thus the mirror field, when the scheduling rule is determined. Traversing the sizing of the heliostats, the width and height of each pair of heliostats corresponds to an initial mirror field through the Campo alignment rule. The optimal alignment of the initial mirror field and the annual average thermal power can be obtained through the adaptive gravitational search algorithm. The values of the optimization parameters such as heliostat coordinates, heliostat sizes, mounting heights, and the number of heliostats under this alignment are output to obtain the annual average of the heliostat field under the optimization parameters. Optical efficiency, annual average output thermal power, and annual average output thermal power per unit mirror area are obtained under the optimized parameters.