This study investigates the influence of thermal history (molding temperature and cooling rate) on the mirror forming process for spin-cast aspheric mirrors. Abaqus finite element analysis software using different molding temperature and cooling rate of simulation analysis to determine the Spin-cast temperature is 950 ℃ and the cooling rate of mirror is 1 ℃/s which can be completed in the mold filling and mirror forming. The spin-cast experiment was executed, and the forming results were measured. When the cooling rate is more than 1 ℃/s, the mirror is fragmented owing to the excessive local residual stress after cooling. Additionally, the axial height of the mirror edge differs from the theoretical value by 10.12 mm, and there is a large surface figure error. This surface figure error is attributable to the volume change on cooling.