Solid-liquid separation technology has been one of the key technologies in water treatment. Air flotation method is the best choice for removal particles with gravity the same as water. This machine is designed by the principle of “shallow tank theory” and “zero-speed”, integrates flocculation, air flotation, skimming, sedimentation and sludge scraping, symbols high-effective and energy-saving water purifying device. First, it is used for waterworks to remove algal and descend turbidity with lake water as water source, Second, it is used for industrial water treatment such as petrochemical, paper mill, textile, printing, electroplate, leather, food industries etc. Third, it is used for recovery of valuable products from sewage such as fiber recovery from paper mill water and wood pulp water.