The invention provides a barley pest protein health-care product and a preparation method thereof. The method comprises steps as follows: dried pest bodies of barley pest larvae, pupae or adults are taken as a raw material, and the raw material is crushed into the particle size of 0.1-1 mm by a dry crusher; circular digestion degreasing is performed with an ethanol solution with the concentration being 60%-95%; protease hydrolysis is performed under the conditions that the pH value ranges from 5 to 9 and the temperature is 30-60 DEG C for 1-10 h, and the mass concentration of protease is 1%-5%; water-insoluble substances are removed through centrifugation or filter pressing; 50%-90% of water and inorganic salt in a system are removed through filtration by a nanofiltration membrane; finally, drying is performed through a spray drying or freeze drying process, and a finished product is obtained. The protein health-care product taking barley pest as a raw material is provided and has a remarkable health-care effect. Mouse tests prove that the health-care product has anti-fatigue and athletic injury recovery promoting effects on mice.