Functional training is one of the most advanced training ideas and has been extensively applied to the training of highlevel athletes, but it is seldom used in the specific teaching of sports in colleges and universities. This paper takes the influence of functional training on the physical fitness of college students majoring in tennis as research object, and uses experimental methods to analyze the changing status of the physical fitness of the students before and after experiments. The results show that, compared with traditional training methods, the functional training is more comprehensive and more pertinent than traditional training methods and plays a more active role in boosting physical fitness quality of the students. The muscle activation training, weightbearing training, trunk stabilization movement mode, recovery training and so on in the functional training have more significant promotion effect on muscle strength, rapid reaction ability, waist and abdomen strength and balance ability respectively, which can provide the basis for technical play of the students majoring in the tennis.