The utility model provides a chemical fertilizer feedstock feeding hopper. The chemical fertilizer feedstock feeding hopper comprises a hopper body. A feeding port is formed in the upper portion of the hopper body, a discharging port is formed in the lower portion of the hopper body, and a material screening assembly is further arranged inside the hopper body. The material screening assembly comprises a screening plate, two sliding blocks and two sliding rails, wherein the screening plate fits with the section of an inner cavity of the hopper body in shape, the sliding rails are fixedly connected to the side wall of the inner cavity of the hopper body, the sliding blocks matched with the sliding rails are arranged on the side walls of the two sides of the screening plate, and the screening plate is assembled between the sliding rails through the sliding blocks; a vibration motor is arranged on the outer wall of the hopper body. Powdery materials are forced to flow through vibrating force of the vibration motor, meanwhile, the screening plate can move slightly in the direction of a sliding groove under the driving of the vibration motor, and the powdery raw materials are further forced to be scattered and flow to pass through the discharging port of the hopper body.