The invention discloses a composite floor turning conveying and gap feeding plate overturning device. The device comprises a conveying mechanism, a limiting mechanism, a lifting mechanism, a chute mechanism, a conveying chain mechanism and a blocking mechanism. The limiting mechanism is located at the front end of a roller assembly. Two parallel belt conveyors are mounted on a lifting rack assembly in the lifting mechanism, and the belt conveyors are arranged in the roller assembly in a staggered manner. The tail ends of the belt conveyors are located above a chute. The conveying chain mechanism comprises a pair of short-pitch conveying chains. Multiple square blocks separated at equal intercepts are arranged on the short-pitch conveying chains. The blocking mechanism is located below thechute mechanism. The device can cooperate with a former plate stamping procedure, next plate overturning continues to be carried out, the steps of manual turning and overturning are replaced, by meansof ingenious design, integrated work of reversing, aligning, overturning and separating of plates can be completed, a large quantity of manpower and financial resources are saved, the device works safely and reliably, and turning conveying and gap feeding can be efficiently completed.