The invention provides a protective cover for an outdoor photochemical comprehensive experimental system. The protective cover is arranged on the outer side of a smoke chamber and has a foldable fan blade-shaped structure; during the experiment, the protective cover can be folded and shrunk, the smoke chamber is opened and exposed from the middle, when the experiment is not implemented at ordinary times, the protective cover can be unfolded and folded from two sides, and the smoke chamber is shielded inside the protective cover. Compared with the existing data, the invention completely introduces the structure, installation, debugging and other details of the protective cover for the outdoor photochemical comprehensive experimental system in details, the protective cover can be used for reference and implemented for technicians in the field, and any creative labor is not required to be consumed. The protective cover for the outdoor photochemical comprehensive experimental system has a good sealing effect, and the rain and snow can be prevented from entering the protective cover, so that the smoke chamber can not be damaged.