The invention belongs to the technical field of polyester optical film production, particularly relates to a casting sheet mold head automatic control system for a polyester optical film, and aims to solve the problems that in the prior art, automatic dust removal cannot be implemented in a mold head casting sheet, the product quality of a film in the next process cannot be guaranteed, and the production efficiency is low. The system comprises a main machine system and an auxiliary machine system; the main machine system comprises a main machine filter, a first main machine pipeline, a mold head exhaust hood, a mold lip positioning point, a mold head, a mold lip, a cold drum, a hot wire pipe, a front mold lip heater and a mold head temperature assembly; the auxiliary machine system comprises a first auxiliary machine pipeline, an auxiliary machine filter, an auxiliary machine system, a numerical control system, a dust cover, an adapter and a second auxiliary machine pipeline; and the first main machine pipeline is connected with the first auxiliary machine pipeline. By utilizing the principle of electrostatic adsorption and humidification dust falling, dust particles can be automatically removed in the mold head casting piece, so that the product of the film in the next process is ensured to be free of defects, and the production efficiency is improved.