The invention discloses a double-protein sports milk and a preparation method thereof. The preparation method comprises the steps of hydration, burdening, homogenization, sterilization, filling and the like. The double-protein sports milk is prepared from soybean protein powder, whey protein powder, casein powder, raw milk, dietary fiber, fat or fatty acid, sugar or a sweetening agent compound stabilizer, and a thickening agent as the raw materials, is thick in taste, sufficient in milk fragrance and convenient to drink, and is an optimal selection of protein supplement food for general sportscrowds. Meanwhile, through scientific animal and plant protein collocation, the amino acid supply duration is prolonged, muscle nutrition and energy supply in the sports process are guaranteed, the sports performance is effectively improved, the sports injury risk is reduced, and the recovery effect after sports is improved.