A folding worktable including a frame and a board is disclosed. The frame has a pair of long borders, a pair of short borders and a number of support bars connected between the long borders. The board is locked on the frame. The worktable has four legs with telescopic units and four retractable folding braces for folding the legs. Each pair of retractable folding braces is connected to a different support bar. There are four casters on the four corners under the frame. When the retractable folding braces are folded and the legs are stored within the frame, the casters touch the ground. The board is a double sided board including a work-board and an anti-skid board which are fixed together. The worktable can also be used as a scaffold, a carrier and a repair skateboard.