In response to the development needs of miniaturization and integration of satellite payload technology, as well as the bottleneck issues of high power and low passive intermodulation in space applications, this paper proposes a design method for a TE101 mode waveguide filter that is easy to 3D print, based on the characteristics of integrated forming technology of 3D printing and filter synthesis theory. A waveguide filter in the Ka band was designed and processed using 3D printing technology, with the entire filter structure formed in one piece. The measured and simulated results are in good agreement; the weight is 70% of that of the traditional screw fastening scheme of the same size; the filter's return loss is better than 22 dB, the in-band insertion loss is better than 0.3 dB, and the equivalent Q value before plating is about 1 100. Simulation results show that this filter has characteristics such as single-mode operation bandwidth and large power capacity; at the same time, the filter structure is suitable for integrated forming by 3D printing, eliminating the need for assembly and adjustment, and avoiding the nonlinear contact caused by the connection between the traditional filter cavity and the cover plate. The measured passive intermodulation level of the filter is lower than -130 dBm,which verifies the accuracy and feasibility of 3D printing technology for filter processing. It is of great significance for the integrated design and engineering application of 3D printed broadband filters.