In　this　paper,　a　nonlinear　servo　control　method　based　on　finite-time　observer　is　developed　for　position　control　of　permanent　magnet　synchronous　motor　(PMSM).　The　nonlinear　servo　control　law　consists　of　two　parts,　where　the　linear　part　is　responsible　for　the　fast　dynamic　response　and　the　nonlinear　part　is　responsible　for　reducing　the　overshoot　when　the　system　approaches　the　steady　state.　To　tackle　the　time-varying　uncertainty　occurring　in　the　system,　a　finite-time　extended　state　observer　is　proposed　to　estimate　the　lumped　disturbance　for　feed-forward　compensation　in　the　control　loop.　Simulation　and　experimental　results　verify　that　the　proposed　control　scheme　can　track　the　target　position　quickly　and　accurately,　and　is　robust　against　disturbance　and　uncertainty.