To solve the problem of sapphire windows being prone to water accumulation and affecting observation and imaging in marine environments, on the basis of a three band anti-reflection film preparation on sapphire substrate, submicron hollow microsphere framework structure is prepared by self-assembly technology in this paper. The chemical immersion is employed for compositing nanoparticles and forming micro-nano composite structure, which overcomes light reflection and scattering at the submicron scale, and achieves an excellent combination of high transmittance and superhydrophobic properties. After preparation, high temperature, low temperature, humid heat, and salt spray tests are conducted according to the requirements of the optical film environment screening test. After the tests, there is no change in the optical properties and hydrophobicity, maintaining a good hydrophobicity angle of 150°. The experimental results show that the prepared superhydrophobic window has good hydrophobicity and environmental durability, which can meet the long-term use needs of sapphire windows in complex environments.