The invention discloses an overhead line system operation vehicle operation table connecting device comprising the following units: a main station connecting module arranged on the rear operation table, wherein the rear operation table serves as the main station; a first slave station connecting module arranged on the front operation table, wherein the front operation table serves as the first slave station, the first slave station connecting module is provided with a first interface module and a DI module, and the DI module is connected with the first interface module through a back plate bus; a second slave station connecting module arranged on a hydraulic operation table, the hydraulic operation table serves as the second slave station, the second slave station connecting module is provided with a second interface module and a DI/O module, and the DI/O module is connected with the second interface module through the back plate bus; a DP bus, wherein the main station connecting module is connected with the first slave station connecting module and the second slave station connecting module through the DP bus. The overhead line system operation vehicle operation table connecting device can save space, can reduce wiring errors, and is convenient in later period maintenances.