A microalgae powder conveying and sterilization device, comprising a first agitating mechanism (1) and a first sterilization mechanism (2); the first agitating mechanism (1) comprises an agitating hopper (11), an agitating motor (12), an agitating shaft (13), an agitating screw (14), and an agitating feeding blower (15); the first sterilization mechanism (2) comprises a sterilization column (21), a sterilization feeding blower (26), a sterilization screw friction device and magnetrons (25); the sterilization column (21) is of a cylindrical structure, and the sterilization column (21) is internally provided with a sterilization chamber; a sterilization feeding pipe (212) is provided on the upper end of the sterilization column (21), and a sterilization discharge port (211) is provided on the lower end; the sterilization feeding blower (26) is mounted on the sterilization feeding pipe (212); the sterilization screw friction device is mounted in the central portion of the sterilization chamber; a plurality of magnetrons (25) are mounted on two sides of the sterilization column (21) from top to bottom; and an agitating discharge port (111) and the sterilization feeding pipe (212) are in communication with each other by means of a conveying connection pipe (5). The microalgae powder conveying and sterilization device has good sterilization effect and high sterilization efficiency, microalgae powders obtained therefrom contain no cancerogenic substance, and the nutrition of the microalgae powders is not lost.