The SSB three-layer forming fabric adopts a three-layer structure design of upper, middle and lower. The upper layer adopts a smaller diameter diameter, weft and plain weave structure to improve the retention of fine fibers and fillers, The paper web marks are light and easy to peel off. The lower layer adopts larger diameter wires and weft wires to improve the stability and service life of the forming mesh structure. In the middle, a pair of wefts are used to precisely connect the upper and lower layers into a whole, so that the upper and lower layers do not produce relative twisting and slipping. The three-layer forming fabric has good paper quality, strong dewatering ability, high vertical and horizontal stiffness, good running stability, and long service life.