The　conventional　speed　predictive　control　system　of　permanent　magnet　synchronous　motor　has　two　major　drawbacks:　the　weight　coefficient　between　the　speed　and　current　term　of　the　cost　function　being　difficult　to　determine,　and　the　selection　of　control　voltage　vector　by　the　traversal　mode　resulting　in　a　large　amount　of　calculation.　A　fast　speed　predictive　control　based　on　expected　voltage　vector　is　proposed　to　regulate　speed.　The　motor　speed　model　was　discretized　by　Taylor　series　to　obtain　an　expected　voltage　vector,　and　the　error　terms　of　the　speed　and　d-axis　current　in　the　cost　function　were　converted　into　voltage　dimension,　which　avoids　the　adjustment　of　the　weight　coefficient.　The　Clark　transform　was　used　to　calculate　the　angle　of　the　expected　voltage　vector　to　describe　the　local　section　of　the　expected　voltage　vector.　The　basic　voltage　vector　constituting　the　local　sector　was　used　as　candidate　voltage　vectors　to　be　substituted　into　the　cost　function,　and　the　candidate　voltage　vector　with　the　smallest　cost　function　was　used　as　the　control　voltage　vector　to　regulate　the　inverter.　The　simulation　and　experimental　results　show　that　the　proposed　method　can　achieve　the　same　steady-state　error　as　that　by　the　conventional　method　with　the　optimal　weight.　The　proposed　method　is　convenient　for　practical　application　without　adjusting　the　weight　and　saves　55%　in　the　calculation　step.　©　2020,　Harbin　University　of　Science　and　Technology　Publication.　All　right　reserved.