Abstract: By introducing the structural features of two kinds of vertical looper, expounding the troubles of the vertical looper trolley overturning,and exemplifying the influencing factors of the looper trolley overturning, the countermeasures and treatment points of the looper trolley overturning fault were summarized in this paper. The main points of maintenance of functional accuracy of vertical looper were also expounded.

Key words: vertical looper, looper trolley overturning, treatment points