In　this　paper,　a　novel　self-interference　(SI)　suppression　scheme　based　on　Dempster-Shafer　(D-S)　evidence　theory　is　proposed　to　cancel　self-interference　in　two-way　full-duplex　(FD)　MIMO　relay.　D-S　evidence　theory　can　appropriately　characterize　uncertainty　and　make　full　use　of　multiple　evidence　source　information　by　Dempster＇s　combination　rule　to　obtain　reliable　decisions.　Instead　of　traditional　spatial-domain　suppression　schemes,　the　proposed　DS-Sum　and　Difference(SAD)-PNC　scheme　adopts　D-S　evidence　theory　to　detect　the　sum　and　difference　signal　for　two　source　nodes　considering　the　SI　cancellation　in　obtaining　basic　probability　assignment　(BPA)　function　in　the　multiple　access　(MA)　phase.　For　comparison,　Log-Likelihood-Ratio　(LLR)　combining　technique　is　extended　for　FD　mode　with　SI　suppression　considered　in　soft　information　computation　for　network-coded　symbol.　In　the　broadcast　(BC)　phase,　antenna　selection　scheme　is　adopted　to　achieve　full　transmit　diversity　gain.　Simulation　results　reveal　that　the　proposed　DS-SAD-PNC　scheme　obtains　better　end-to-end　average　bit　error　rate　(BER)　performance　compared　with　extended　MIMO-LLR-PNC　and　traditional　spatial-domain　suppression　schemes　like　ZF　and　MMSE　with　a　little　complexity　increased.