The high precision theoretical design of the filter and the small error process are discussed. A variety of design experiences are summarized, and several types of filter design schemes are investigated. The appropriate filter structure is selected to design and process the 110 GHz inductive window coupling waveguide filter. The design adopts the inductive window coupling structure, which is realized by traditional machining technology and integrated with the flange structure. Based on High Frequency Structure Simulator(HFSS), a 110 GHz band-pass filter is designed and fabricated. Its central frequency is 110 GHz, relative bandwidth is 5%, insertion loss is less than 1 dB, the in band return loss is more than 20 dB, and the out of band suppression is more than 40 dB at a bandwidth twice the center frequency.