The invention provides a transformer substation operation and maintenance pull rod tool cart of a three-idler-wheel structure, and relates to the field of transformer substation operation and maintenance. Currently, when power failure and power transmission operation is normally conducted, a tool chamber is far from a primary equipment area, many operation tools exist and need to be carry many times, and the additional workload of operation team personnel is increased. The transformer substation operation and maintenance pull rod tool cart comprises a baseboard, a vertical support, an object storage box, two sets of trundles and a pull handle, an operating ticket clamp is arranged at the right side of the middle of the support, an operating ticket platform capable of turning downwards is arranged at the right side of the upper portion of the support, an insulating rod electroscope placing platform is arranged at the left side of the upper portion of the support, both sets of trundles are of the three-idler-wheel structure in which every two idler wheels are spaced by 120 degrees in a vertical plane, and one idler wheel is connected to the right side of the lower portion of the support; a two-connecting rod foldable supporting structure is arranged between the lower portion of the operating ticket platform and the support. By means of the transformer substation operation and maintenance pull rod tool cart of the three-idler-wheel structure, carrying multiple tools is achieved simultaneously, a multifunctional processing platform is provided, the carrying workload is reduced,the carrying work intensity is lowered, so that an operation and maintenance fault is more conveniently processed, and the processing time is shortened.