Based　on　the　collected　data　to　carry　on　the　analysis,　found　that　the　CNC　system　in　the　CNC　grinding　machine　fault　rate,　a　large　part　of　the　station,　the　reliability　growth　of　CNC　system　is　studied　in　the　paper,　CNC　system　parameter　selecting　principles　of　reliability　growth　are　particularly　discussed.　CNC　system　reliability　ideal　growth　curve　is　settled　to　CNC　system　reliability,　Thus　increasing　CNC　system　to　improve　the　reliability　of　CNC　grinder　machine　reliability　is　of　great　significance.