Bag opening system and bag opening method

The bag opening system comprises a ton bag conveying mechanism, a bag opening mechanism, a waste bag packaging mechanism, a waste bag transferring mechanism and a ton bag transferring mechanism, and the ton bag conveying mechanism conveys and lifts ton bags full of materials; the bag opening mechanism cuts the opening of the ton bag and releases materials; the waste bag packaging mechanism recovers empty bags; the waste bag transfer mechanism transfers the empty bags from the bag opening mechanism to the waste bag packaging mechanism; the ton bag transferring mechanism transfers the ton bags filled with materials to the bag opening mechanism from the ton bag conveying mechanism; the middle of a ton bag is held by the ton bag transferring mechanism in a four-side surrounding mode, so that the bottom face of the ton bag is a flat square surface, and the ton bag can be cut open from the outer edge of the bottom face of the ton bag through the bag opening mechanism. According to the ton bag transfer mechanism, th