The invention discloses an anti-loosening bracket joint device with multiple friction plates. The anti-loosening bracket joint device comprises a rotary base, an adapter crankshaft, an adapter block, a locking bolt, a locking cover, a first friction plate, a rotary shaft, a second friction plate (number of friction plates can be increased), a rotary head rotation block and a hanging plate assembly, wherein the rotary base is fixedly arranged on parts such as a desktop and a wall through connection or other joints; the adapter crankshaft, the rotary base and the adapter block form a rotary pair; the locking cover is blocked with the rotary head rotation block through the locking bolt; the rotary shaft penetrates through the center of the first friction plate, the center of the second friction plate and the center of a square hole bearing, and is positioned in a cavity which is formed by fixedly connecting the locking cover and the rotary head rotation block; and the rotary head rotation block is connected with the hanging plate assembly through a blocking pin. According to the anti-loosening bracket joint device disclosed by the invention, multiple friction plates are adopted, so that friction surfaces and axial pressing are increased, and therefore, greater friction force can be obtained. The anti-loosening bracket joint device is reasonable in design, is simple in structure, and is suitable for the optimized design of the anti-loosening bracket joint device.