Good contact conditions between the pantograph and catenary ensure the safety of electrified railways. However, the relevant state-of-the-art status inspection methods cannot achieve high speed, and robust effects under complex conditions, such as multi-suspended line interference, unknown complex backgrounds, and light and dark changes. Therefore, a two-module contact status diagnosis methodology, consisted of long-term tracking and 3D reconstruction, is proposed in this study. This long-term tracking method is a combination of tracking, detection and discrimination, focusing on locating the contact area of high-speed movement in complex environments. First, a brand-new tracking paradigm, namely, GMSTrack, based on feature matching is developed to adapt to complex background changes. Second, we modify the loss function via GloU-plus loss for box regression and via adaptive wing loss for landmark regression on CenterNet and realize a dramatic improvement in detection accuracy at 125 FPS. Third, sequential information is collected for the transformer-based discriminator to evaluate the correctness of the current tracking result. Experimental results show that the optimal strategy that combines tracking, detection, and discrimination can locate the contact area in complex environments with an accuracy higher than 93% and with a speed higher than 84 FPS. Lastly, dynamic stagger value and height of conductor that can reflect contact status are analyzed though 3D reconstruction of the binocular contact points. The overall status inspection methodology can be applied to the on-site high-speed trains at speeds exceeding 80 FPS.