Abstract: ［Objective］ Since the metro system suffers from abnormal wear problem of contact wires, it is necessary to explore the data correlation degree between the key data of the pantograph catenary (PC) system and the contact line wear thickness. ［Method］ PC tests are conducted on the actual line, and measured data such as dynamic contact force, train running speed, vertical acceleration of the contact strip, arcing duration, bus current, catenary stagger value and contact wire wear thickness are obtained. The proportion of each factor′s contribution to the wear thickness of contact wire is analyzed by grey correlation method. ［Result & Conclusion］ The train running speed directly affects the wear thickness of the contact wire, and its influence accounts for the largest proportion, followed by the dynamic contact force. Other factors are ranked from large to small in terms of influence proportion as follows: arcing duration, bus current, catenary stagger value, and vertical acceleration of the contact strip.