After implementation the new competition system of badminton 21 points every service is scored, it has drawn a mixed response from every country athletes, coaches and umpires. This paper utilizes classical probabilistic model establishing relationships between one rally winning probability and one game winning probability, through observation it adopts hyperbolic tangent curve fitting images method to simplify the express formulas, from which it raises two evaluation indicators model that are occasionality indicator and intensity indicator. To occasionality indicator, it defines through hyperbolic tangent functions inclination, and so gets conclusions that occasionality by adopting 15 points three out of five sets is 20% above that of 21 points three out of five sets; While for competition intensity indicator, we use single match winning probability’s approximate degree to 0.5 to represent. For comprehensive evaluation model indicator, it adopts variable weight functions optimal indicator evaluation model to determine, defining one variable weight function to distinguish occasionality elements and intensity elements weights when values of are different. TOPSIS method evaluation model, by calculating every evaluation objects distance from ideal solution and negative ideal solution, then makes comparison and so gets 4 kinds of competition systems comprehensive evaluation. Every competition system doesn’t have absolute advantages or disadvantages. This paper adopts relativity analysis and comprehensive evaluation analysis four schemes that mentioned in subject, it is known those 21 points two out of three sets and 15 points three out of five sets are reasonable competition systems.