Through researching Olympic Games gymnastics team competition grading rules, discuss gymnastics team competition equity , find grading rule is not fully conform to four criterions in some conditions, grading equity is different and has some shortcomings. To perfect grading rules equity, make it meanwhile meet four criterions, propose a grading rule according to integral function. Olympic Games grading rules have four items, combining with Olympic Games grading examples, discuss grading rules have shortcomings examples in some conditions. And according to 2008 Beijing Olympic Games and 2012 London Olympic Games, men gymnastics event score table, put forward improvement rules targeting with grading rules shortcoming aspects. Carry out inhomogeneous difference handling with men gymnastics scores, fit out men gymnastics integral function. Make grades with fitted men gymnastics integral function. Fitted function refines different sections grades ’score, according to competition different grades’ ranks corresponding score difficulty and easiness extend, convert difficulty and easiness into scores, and similarly also record into grades. In this way it can avoid grades inequity due to different difficulty and easiness extent grades. Grading rules after improvement is conform to four judge criterions; it has higher equity than original criterion.