There are numerous applications for multispectral filter film, including remote sensing detection, medical treatment, and military camouflage recognition. The process of preparing it is complex, which has resulted in a high price tag and low yield. We use electron beam evaporation to create five-spectral-band filter films between 380 and 900 nm using Ta2O5 and SiO2. Multispectral filter films with different bandwidths are designed using multiple methods derived from thin-film theory. Using the characteristics of each channel spectrum, three methods of monitoring film thickness were combined to prepare each channel: crystal oscillator monitoring, back-reflection monitoring, and optical transmittance monitoring. Using mechanical masks to prepare each channel individually, the transmittance over the passband is greater than 95%, and the spectral rectangle meets the requirements of applications.