According to the shape, the special-shaped steel pipe is divided into: outer hexagonal inner round steel pipe, outer round inner hexagonal steel pipe, inner and outer hexagonal steel pipe, flat oval steel pipe, oval steel pipe, triangular pipe, L-shaped steel pipe, octagonal pipe, mushroom-shaped pipe, bread-shaped pipe, D-shaped pipe Tube, concave tube, convex tube, umbrella tube, P-shaped tube, ingot-shaped tube and other special-shaped steel pipes, the shape of the special-shaped steel pipe is produced according to the needs of users