The invention discloses a processing method of an optical prism. The method comprises the steps that 10, a glass tooling and a lens are bonded together with glue to form a cohesive body, wherein the glue is composed of a photosensitive adhesive, a reinforcing agent and a thermal expansion agent; 20, the cohesive body is fixed on a milling and grinding table; 30, the lens is processed; 40, the cohesive body and the milling and grinding table are separated; 50, the cohesive body is soaked with water with a first temperature and water with a second temperature alternatively for the scheduled duration so as to separate the lens from the glass tooling, wherein the first temperature is greater than the second temperature. According to the processing method of the optical prism, the glass tooling and the lens are bonded with the glue, the bonding effect is good, when the glass tooling and the lens are separated, soaking is conducted with water with different temperatures alternatively, the safety coefficient is high, and the production cost of the optical prism is reduced.