Abstract: biaoThe leakproofness test method for field coating of welded joint of pipeline coating materials and the selection of coating material are introduced in the paper. By means of the test, t he actual sealing quality of a heat shrinkage sleeve and/or tape (coating material used in field coating of wel ded joint) to some special external coating materials and different heat shrinkage sleeves and/or tapes to special external coating material as well as application differences in different diameters of pipeline are inspected. The poor performance in leakproofness of coating materials is analyzed. This test method establ ished is directive to the selection of coating materials with availability and reliability in methodology.