A　variable　power　reaching　law　for　sliding　mode　control　is　proposed　aiming　at　reducing　the　chattering　phenomenon　in　traditional　sliding　mode　control　methods　and　speeding　up　the　convergence　speed.　The　proposed　reaching　law　adjusts　the　convergence　process　adaptively　by　using　a　variable　power　term,　so　that　the　system　has　anobviously　faster　convergence　and　has　no　chattering　phenomenon,　and　it　also　has　the　characteristic　of　global　finite-time　convergence.　It　is　proved　that,　for　a　class　of　bounded　external　disturbance,　the　sliding　mode　variable　converges　to　a　preset　steady-state　error　with　the　boundary　layer　width　of　about　1　within　finite　time,　and　the　value　of　the　steady-state　error　is　less　than　the　existed　reaching　laws　such　as　double　power　reaching　law,　the　fast　power　reaching　law,　and　so　on.　Simulation　results　are　given,　which　demonstrate　the　validity　and　superiority　of　the　proposed　method.　©　2019,　Editorial　Department　of　Journal　of　Chinese　Inertial　Technology.　All　right　reserved.