In　this　paper,　a　priority　sorting　approach　based　on　simplified　model　predictive　control　(MPC)　is　proposed　for　modular　multilevel　converter　(MMC).　It　aims　at　reducing　the　computational　burden　of　conventional　MPC　method　while　maintaining　the　system　performance,　especially　under　high　voltage　levels.　The　proposed　approach　mainly　consists　of　three　parts,　i.e.,　grid-side　current　control　(GCC),　circulating　current　control　(CCC),　and　capacitor　voltage　balancing　control　(CVBC).　The　GCC　and　CCC　are　separately　designed　with　simplified　MPCs,　avoiding　the　weight　factor.　Meanwhile,　the　redundant　calculations　are　eliminated　in　GCC　by　considering　the　desired　predicted　output　voltage　of　equivalent　MMC　model.　To　further　minimize　the　optional　combinations　of　the　switching　states,　the　CCC　is　constructed　by　utilizing　the　output　of　GCC　and　the　arm　current.　Besides,　a　novel　priority　sorting　approach　is　proposed　for　the　CVBC　to　alleviate　the　sorting　operation.　The　submodules　are　divided　into　three　groups　according　to　the　detected　capacitor　voltages.　Moreover,　the　groups　are　assigned　with　different　priorities　based　on　the　arm　current,　and　only　one　group　needs　the　sorting　process.　Additionally,　a　reduced　frequency　approach　is　introduced　to　decrease　the　power　loss　in　the　steady　state.　The　effectiveness　of　the　proposed　approach　is　validated　by　both　simulation　and　experimental　results.