Screw pump is a new type transporting liquids machine which has advantages such as simple structure, safe and reliable operation, convenience usage and repair, continuum and level liquids discharging, stable pressure. The metal spare parts contacted with medium are made up of perfect stainless acid-endure steel, sleeve is made up of non-poison non-smell latex, operating temperature can reach 120. So it has advantages such as rotten preserve, acid endure and oil endure, especially transporting apiece density food slurry. Otherwise, it can transport no containing solid grain or gel liquor, slurry, hanging liquid, glue whose density is between 1 CP and 1000000 CP in chemical, petro-chemical and sewage dealing process.