A production process and device for an environmentally friendly expansion-type steel structure fireproof coating, the production device comprising a base, feeding apparatuses, a stirring apparatus, an auger apparatus, a grinding apparatus, a finished product hopper assembly, and an up-down floating apparatus, wherein the feeding apparatuses are located at the topmost end of the device, and after raw materials reach a set quality value, the feeding apparatuses are opened at the same time to allow the raw materials to enter the stirring apparatus, such that the raw materials are uniformly fed, and are stirred more uniformly. According to the present invention, during stirring, the raw materials at the bottom enter a floating grinding machine for grinding; after a certain type of grinding, the raw materials enter a bottom screening frame; the raw materials of large particles return to the top of a stirrer through an auger conveying channel for stirring; the up-and-down movement height of a grinding body can also be adjusted according to the completion amount of grinding, such that the raw materials are better ground, and the grinding efficiency is improved; and during the whole process, stirring and grinding are performed at the same time, such that the procedures are reduced, the working efficiency is improved, the production time is further saved on, and the production cost is reduced.