The traditional W-band power combiner is difficult to integrate with other planar circuits because of its large size, which limits its application in small platform. To carry out research on high efficiency and small size power combiner. In this paper, we present a novel two-way waveguide power combining structure which uses multiplayer silicon bulk micromachining techniques. A good performance is achieved by utilizing MEMS and three-dimensional wafer bonding stacking technology. Within the operating band from 90GHz to 96GHz, the return loss is better than 22.5dB, the insertion loss is less than 0.22dB and the simulated result demonstrates an overall combining efficiency of 95%.