Applying TV goniometry to measure the angle deviation and rotation angular velocity of missile deviated from the line of sight,and it has the advantage of high precision and low bias. Using of thin-film technology to improve performance of TV goniometry optical system is a more effective method. Based on the thin-film design theory,and metal-medium structure was used to design broad spectrum splitter film and internal reflecting film. This method solves the problem of polarization separation when a wide spectrum incident obliquely. By optimizing the deposition process and ion-assisted parameters,using vacuum annealing method to solve the problem of internal reflecting film stripping. After testing,the prepared film meets the requirement of the system and passes the relevant environmental tests of national military standard.