Two kinds of thin-film with full different physic performances are combined together on K9glass substrate to form composite film layer,achieving anti-electromagnetic interference and high light-transmitting.Technical performance index:light-average transmissivity is not less than 90%in 400nm-1100nm.The resistance value on anti-electromagnetic interference shielding surface is 4±0.5Ω/口to achieve a good anti-electromagnetic interference shielding.A complex film construction composed of electromagnetic interference resistance and reducing reflecting coating is designed to meet the technical performance requirements and coating experiment is carried out.The experiment result shows that microstructure of optical thin film can be improved by ion assisted deposition technology to increase optical performance,physical performance and durability of complex thin film.