The invention belongs to the field of sewing machine backstitch, and relates to a needle pitch adjustable precise reverse seam driving mechanism of an electric sewing machine. The technical problem that the stitch of a backstitch and the stitch of a seam in the backstitch cannot be aligned in the prior art is solved. The needle pitch adjustable precise reverse seam driving mechanism of an electricsewing machine comprises a tooth frame, wherein the tooth frame and a tooth lifting shaft and a feeding shaft are rotatably connected; a sewing machine head is rotatably connected with a backstitch adjusting shaft; the backstitch adjusting shaft is connected with the tooth lifting shaft through a first connecting rod; the first connecting rod is adjustable connected with the backstitch adjustingshaft; the backstitch adjusting shaft is connected with a backstitch rotary driver for driving the backstitch adjusting shaft to rotate circumferentially. Compared with the prior art, the needle pitchadjustable precise reverse seam driving mechanism of an electric sewing machine has the advantages of adjustable backstitch stitch.