Flight cadets need to have good physical fitness to cope with the challenges of flying missions. The continuous development of science and technology has led to the constant upgrading of fighter jets and the improvement of their performance, which has resulted in new and higher requirements for the physical fitness of flight personnel. The traditional physical training mode, method, and assessment have been used for many years and do not meet current fitness needs. To investigate the impact of a 12-wk comprehensive anti-G fitness training program on the aerobic capacity of aviation cadets and to evaluate its effectiveness. Fifty-five cadets were randomly assigned to control and experimental groups using a randomized, single-blind design. The control group maintained their existing training regimen, while the experimental group participated in a 12-wk comprehensive training intervention. The training program comprised strength training twice per week, high-intensity interval training three times per week, and supplemental nutritional and psychological support. Maximal oxygen uptake (VO2max), lower limb strength, and hemoglobin levels were measured at baseline, at 6 wk and 12 wk post-intervention. Repeated measures analysis of variance revealed significant differences of both VO2max and relative VO2 in both groups across time points (P < 0.05). However, no significant time-group interaction was observed (P > 0.05). Paired t-tests comparing baseline and 12-wk results showed that VO2max and relative VO2 were significantly higher in the experimental group than the control group (P < 0.05). This suggests that the training program effectively enhanced the aerobic capacity of the experimental group. Key indicators of aerobic capacity, bilateral lower limb strength and hemoglobin levels, were also significantly different over time and between groups (P < 0.05). No significant differences were noted in heart-rate metrics (P > 0.05). A 12-wk comprehensive anti-G fitness training program significantly improved the aerobic capacity of aviation cadets, thereby enhancing their overall capacity and laying a physiological foundation for enduring high-G flights.