Installation structure, illumination device including installation structure and installation method thereof

The invention relates to an installation structure for fixing an illumination device, and the illumination device including the installation structure, wherein the illumination device comprises a first assembly plate for at least bearing a light source of the illumination device; the installation structure comprises a second assembly plate; the first assembly plate comprises a first assembly unit and a second assembly unit oppositely arranged on the first assembly plate; the second assembly plate comprises a first installation part and a second installation part; and the first installation part is inserted to the first assembly unit, and rotates corresponding to the second assembly plate through the first assembly plate, so that the second installation part is clamped in the second assembly unit or is unlocked from the second assembly unit. In addition, the invention further relates to a method for fixing the illumination device.