The invention provides a staggering preventing device of a sewing material. The staggering preventing device comprises a tooth rack provided with a fixed swinging supporting point, a feed dog arranged at one end of the tooth rack, a rotatable eccentric shaft and a driving mechanism for driving the eccentric shaft to rotate, wherein a first sliding groove is formed in the other end of the tooth rack; the fixed swinging supporting point of the tooth rack is located between the feed dog and the first sliding groove; the eccentric shaft comprises a shaft body part and a shaft eccentric part which is eccentrically arranged on the shaft body part; the shaft body part is connected with the driving mechanism; the shaft eccentric part is rotatably mounted in the first sliding groove of the tooth rack and is in sliding matching with the first sliding groove; when a presser foot is lifted or after the presser foot is lifted, the driving mechanism drives the tooth rack to downward move toward one end of the feed dog on the tooth rack through the eccentric shaft, so that the feed dog is descended to the lower side of a needle plate; a distance between the needle plate and the presser foot in a feeding process before sewing is enlarged and the sewing material is not in contact with the feed dog, so that the material is convenient to feed; a condition that the sewing material has staggering and layering phenomena before sewing can also be avoided.