This letter presents a new design method for multiband filtering crossovers based on mixed spherical cavity resonators spherical/hemispherical cavity resonators (HCRs) using the 3-D printing technology. For realizing cross-transmission and isolation of multiple channels, the degenerate orthogonal modes in the cross unit are fully explored. To achieve the desired multiband response, split-type topology is created by coupling multiple bandpass resonators with band-stop resonators. To verify the method, a dual-band monolithic prototype is fabricated using the stereolithography (SLA) 3-D printing technology, demonstrating reduced assembly loss and complexity. The simulated results and measured results show good agreement, confirming the feasibility of the proposed design method.