To investigate the important index of maximum oxygen uptake in evaluating cardiopulmonary function and to provide a basis for the evaluation of cardiopulmonary function for adolescents, a total of 200 healthy adolescents aged 12–14 were selected, and these 200 subjects were randomly assigned to the modeling group and the test group. In the first stage, data of 150 subjects were randomly selected, and the regression equation for VO2max was established by adding independent variables such as gender, age, height, weight, body mass index, and resting heart rate. In the second stage, the remaining 50 subjects were selected as the test group to test and evaluate the prediction effect of the prediction model. The results showed that the correlation coefficient between the measured value of maximal oxygen uptake and the predicted value was 0.983, and the significance level was 0.000, which was significantly lower than 0.01 correlation, indicating that there was an obvious concomitant relationship between the two values. The maximum oxygen uptake calculated by this equation is good and has a good application prospect.