Adjustable positioning support for welding special-shaped joint of steel member

The invention relates to an adjustable positioning support for welding a special-shaped joint of a steel member. The problem about stable supporting in the welding machining process of the special-shaped joint of the steel member is solved. A cushion block is arranged in the center of a table board of the device, a plurality of arc-shaped grooves with the cushion block as the circle center are formed in the table board, a plurality of adjusting supports capable of sliding along the arc-shaped groove are arranged in each arc-shaped groove, each adjusting support comprises a bottom plate and side plates upwards arranged at the two ends of the bottom plate, the top ends of the side plates are horizontally bent outwards to form turning plates, vertical grooves are formed in the middles of thecorresponding two side plates in an aligned mode, a bracket supporting plate capable of being adjusted up and down is transversely arranged between the corresponding two vertical grooves, the two endsof each bracket supportin