Abstract: Actual product tests are carried out on 80 grade SEW expandable pipe(BX80)and study is made on the sizes, mechanical properties and tensile strength etc.of the pipe after expanding.Results of the tests indicate that the home-made BX80 expandable pipe maintains a relatively low and stable pressure during expanding and the pipe after expanding still has good matching of strength, plasticity and toughness, and its mechanical properties and collapse resistance can meet the requirements of specifications such as API Spec 5CT and API TR 5C3 etc., which shows the home-made BX80 expandable pipe can satisfy the requirements of engineering applications with its easy-to-expand feature and good application performance after expanding.