The invention provides a flag planting component and a street lamp device, and aims at solving the technical problems that the existing mode of planting the flag on the supporting column of a street lamp has poor convenience and short fixing period. The flag planting component comprises a fixing base, a rotating disc and a planting cylinder. The fixing base is used for being detachably connected with the column of the street lamp. The rotating disc is rotatably connected with the fixing base and the rotating disc can be fixed relative to the position of the fixing base. The planting cylinder is connected with the rotating disc and the central axis of the planting cylinder is overlapped with the radial line of the rotating disc.