[Objective] This study aimed to optimize the fermentation process of quinoa-haskap complex fruit fermentation supernatant and develop anti-exercise fatigue food with high nutritional value. [Methods] Using black quinoa and haskap as raw materials, yeast combined with Lactobacillus for collaborative fermentation, the fermentation process conditions of composite fermentation juice were optimized by single factor and orthogonal test, and its anti-exercise fatigue effect on mice was deeply investigated based on animal experiments. [Results] The optimum fermentation conditions of quinoa-indigo fruit complex juice were as follows: initial pH 4.0, fermentation time 32 h, fermentation temperature 37 ℃, white sugar content 8%, and the activity of superoxide dismutase in the fermentation product was 253.49 U/mL. In vitro antioxidant tests showed that composite quinoa-haskap complex fermented supernatant had strong antioxidant effect and proportional to the concentration of antioxidant. The results of animal experiments demonstrated that different doses of quinoa-haskap fruit complex juice fermented supernatant prolonged exhaustive swimming time of mice, significantly reduced serum urea nitrogen and other indexes, and significantly increased liver and muscle glycogen reserves (P＜0.05). [Conclusion] The supernatant of quinoa and haskap fruit complex juice under optimal fermentation conditions has strong antioxidant activity and can improve the exercise endurance of mice.