To provide a post-treatment method for an optically molded article by which an excellent mechanical strength can be imparted to the optically molded article while maintaining a high dimensional precision.

This post-treatment method for the optically molded article is a post-treatment method for the optically molded article constituted by integrally laminating a plurality of curing resin layers, which is obtained by repeating a process wherein the curing resin layers are formed by selectively performing a light irradiation to a light-curing resin. The post-treatment method includes a low temperature post-curing process, and a high temperature post- curing process. In this case, in the low temperature post-curing process, the optically molded article constituted of the curing resin, of which the glass transition temperature (Tg) exceeds 100°C, is heat-treated at a temperature of 50 to 100°C for 1 to 24 hours. In the high temperature post-curing process, the optically molded article, which has been heat-treated in the low temperature post-curing process, is heat-treated at a temperature of (Tg) to (Tg+100°C) for 1 to 24 hours. In the post-treatment method, the optically molded article which has been heat-treated in the high temperature post-curing process, is preferably cooled by a cooling speed of 2°C/min or lower.