The invention provides a flat-topography tower-type photo-thermal solar power generation field heliostat optimization arrangement method, and belongs to the technical field of heliostat arrangement. The method comprises obtaining original materials, comprising geographic information and solar resource information, of a tower-type photo-thermal solar power generation heliostat field, determining influence factors, which influence heliostat optimization arrangement, of an arrangement angle [alpha], the offset spacing ratio I and the longitudinal spacing ratio j and reasonable value ranges of the influence factors, building orthogonal test engineering and calculating corresponding electric quantity according to the determined influence factors and the determined reasonable value ranges, performing a corresponding analysis on an obtained orthogonal test result to determine the best values of the influence factors, and obtaining the best heliostat scheme through integration with the best values of the influence factors. The method solves the technical problem, i.e., how to rapidly find a reasonable relative position relationship of heliostats; and, through selections of the specific parameters, a lot of workload can be saved, and the optimal scheme is obtained rapidly and accurately.