Positive and negative pressure winnowing system for decoration garbage

The utility model discloses a decoration garbage positive and negative pressure winnowing system which comprises a shell, a separation chamber is arranged in the shell, a first conveying belt is arranged on one side of the separation chamber, a second conveying belt is arranged on the other side of the separation chamber, and a fan is fixedly installed on the side wall of the shell. A second conveying belt is arranged on the first conveying belt, a fan is arranged on the second conveying belt, an air blowing opening used for blowing separated light substances of indoor decoration garbage to the position above the second conveying belt is formed in the fan, a negative pressure air chamber is arranged over the second conveying belt, and the negative pressure air chamber is communicated with an air inlet of the fan through an air pipe. And the air blown out of the air blowing opening can flow into the negative-pressure air chamber, so that circular flow of air in the fan, the negative-pressure air chamber and th