This　paper　considers　the　minimax　perturbation　bounds　of　the　low-rank　matrix　under　Ky　Fan　norm.　We　first　explore　the　upper　bounds　via　the　best　rank-r　approximation　(A)　over　cap　(r)　of　the　observation　matrix　(A)　over　cap.　Next,　the　lower　bounds　are　established　by　constructing　special　matrix　groups　to　show　the　upper　bounds　are　tight　on　the　low-rank　matrix　estimation　error.　In　addition,　we　derive　the　rate-optimal　perturbation　bounds　for　the　left　and　right　singular　subspaces　under　Ky　Fan　norm　sin　Theta　distance.　Finally,　some　simulations　have　been　carried　out　to　support　our　theories.