Based on the abrasion in spindle and adhere in inner ring of bearing, shaft sleeve should be added after the repair of spindle to replace the original structure. In order to study the influence of small diameter of spindle after repair to overall strength of ventilator, finite element method was adopted to analyze the spindle with Three-dimensional parametric modeling and static strength, stress and deformation distribution of spindle were got, different diameter of axle affecting integral strength were analyzed, the relative parameters of repairing spindle were settled. The practice showed that the parameters met the needs of strength.