Plastic woven square bottomed open pockets are made of commonly used composite plastic woven cylinder fabric. The bottom of the bag is sealed with a reinforced bottom strip through hot gas welding and bonding. The bottom is square and the bag opening is flat. This is a transitional product that balances traditional and advanced ideas, and users do not need to modify the filling assembly line. After logistics filling, the sealing method of the bag opening can be the same as the packaging sealing method of opening the bag at the bottom. But because the bottom of the bag is square, the overall effect of the filled bag is better than that of the M folded sewn bottom bag, which can be comparable to the square bottom valve pocket. Due to the use of mechanized automatic bag making, bag making enterprises can change the sewing process and reduce the use of sewing workers.