A new type of tube settler with rectangular cross-section and vertical adhesive interface in the tube module is proposed.The tube module by this kind of tube settler has flat top and bottom faces.Experiments show that the tube settler with rectangular vross-section and vertical adhesive interface has the advantages of better sedimentation performance,less material censumption for its construction and no flow transitional section from turbulent flow to laminar flow in the inlet part of the tube of which the whole length takes part in solid-liquid separation.