Steel plastic composite tank series products are anticorrosive equipments which apply rotomolding technology to form the modified PE into internal wall of steel for once time via steel net filtration. It has such advantages as polyethylene anticorrosion, wear proof, without toxicity, impact resistance and long service life. The entirety forming is impervious without welds, steel plastic combination is firm and no delaminating, and the plastic lining layer is flat and smooth without bubbling and crazing as well as it can support positive-negative pressure.