Separator for screening sand and stone

The invention relates to the technical field of sand-gravel separation, in particular to a sand-gravel screening separator which comprises a rack, a pre-screening mechanism, a conveying mechanism and a screening mechanism, and the pre-screening mechanism, the conveying mechanism and the screening mechanism are arranged on the rack. Wherein the pre-screening mechanism comprises a feeding hopper and a pre-separation screen arranged in the feeding hopper, a feeding port is formed in the top end of the feeding hopper, a sand outlet is formed in the bottom end of the feeding hopper, a stone outlet is formed in the side wall of the feeding port, and the pre-separation screen is located between the feeding port and the sand outlet and used for pre-screening gravel; and one end of the conveying mechanism is arranged close to the sand outlet, the other end of the conveying mechanism is arranged close to the screening mechanism, and the conveying mechanism is used for conveying the gravel to the screening mechanism and