Forward and backward movement apparatus for main body of sewing machine according to this invention comprises, in sewing machine comprising Main Body movable forward and backward and supported on both sides of a Base and Heads movable left and right and supported on the Main Body; Frame mounted on the Base; Timing Gears installed in the front and rear Fixed Frame of the Frame in multiple rows; Connecting Shat which connects Timing Gears beneath Front Fixed Frame; Forward and Backward Movement Frames is movable forward and backward on the Frame and connected to the Main Body; Rollers are installed in the Forward and Backward Movement Frames in multiple rows to correspond to the Timing Gears; Timing Belt which zigzags through Timing Gear and Roller and Timing Gear and Roller, and both ends of which are connected to the top of Front and Rear Fixed Frames; and electric motor which drives the Connecting Shat in forward and reverse directions.