Multi-layer sand screening machine

The utility model discloses a multilayer sand screening machine which comprises a support, a spring and a vibration bin, a vibration motor is installed at the bottom of the vibration bin, a feeding hopper is arranged at the top of the vibration bin, a sand screening plate inclining downwards is installed in the vibration bin, one side of the sand screening plate is located at the bottom of the feeding hopper, and the other side of the sand screening plate is connected with a discharging channel. The vibration bin is provided with a clamping groove and a baffle, the sand screening plate is clamped in the clamping groove and erected on the baffle, the vibration bin is provided with a door body assembly capable of being opened or closed, a fixed eccentric throwing block and an adjustable eccentric throwing block are sequentially installed on an output shaft of the vibration motor, and a check ring is arranged at the outermost end of the vibration motor. The fixed eccentric flail block and the adjustable eccentri