The invention discloses a wheel-tracked switchable mobile robot of a transformer substation. The mobile robot comprises boxes, driving mechanisms and obstacle-surmounting support arm mechanisms, and the obstacle-surmounting support arm mechanisms are arranged on two sides of the boxes and composed of wheeled mechanisms and obstacle-surmounting mechanisms in combination. Each driving mechanism comprises a driving wheel mechanism and a driving motor mechanism connected together through a driving mounting plate, the driving wheel mechanisms are connected through a traveling track, and driving wheels are driven to move by the driving motor mechanisms. The mobile robot is simple in structure, flexible and reliable. A main drive system in a body adopts chain drive and is reliable in connection and simple to maintain, and precision can be guaranteed by adoption of chain wheels of a chain; wheels on the obstacle-surmounting support arm mechanisms are connected onto support arm driven shafts through keys and are detachable and convenient to maintain.