The invention discloses a method and a device for producing and using polyprotein breeding premix and utilizing waste liquor. The producing method comprises the following steps: selecting and using hoof and horn wastes of animals, and preparing nutrient solution containing various amino acids and trace elements from the wastes through high-temperature and high-pressure boiling, milling and rubber grinding; adopting the prepared nutrient solution as a nitrogen source and sugarcane sugar as a carbon source to carry out heterotrophic cultivation and propagation of chlorella; and adopting a base material prepared from various natural feeding fibers to continuously adsorb the chlorella to form the premix. The method has rich raw material source and low cost, can solve the environment problems brought by agricultural and animal husbandry wastes, realizes quick acquisition of large biological yield with low cost under simple process conditions, and meets the requirement of industrialized production. The produced feeding premix has high quality, cheap price and wide application, and can be used for preparing complete feed according to different applications and different proportions. The waste liquor of the premix can be supplied to aquiculture, farmland irrigation and fertilization and soil improvement after photoautotrophic propagation so as to realize full utilization of resources and reduce discharge.