Qimin Yaoshu (Essential Techniques for the Welfare of the People), written in the Northern Wei Dynasty, had a specific record of process of boiling down gelatin, it involved 12 steps. Comparing with the methods of later generations, we find that the main differences lie in 6 aspects: shaving hair, adding accessories, duration and degree of heating for gel-forming, preventing gelatin from scorching, drying method, checking water quality. Especially, it is considered that the experience of no hair shaving and excipients adding is of great reference value to the cooking methods of modern donkey-hide gelatin and ox-hide gelatin