The invention discloses a self-walking type pipeline inwall overhauling system. The self-walking type pipeline inwall overhauling system comprises a control host and a self-walking pipeline inwall overhauling integrated machine. The self-walking pipeline inwall overhauling integrated machine comprises a machine body. The machine body is provided with a walking mechanism, a function tool frame and mechanical arms. The walking mechanism comprises a main beam and radial fixing devices which are arranged at the two ends of the main beam. Each radial fixing device comprises a main beam sliding block, a sliding disk and piston shoes. The walking mechanism is fixed to the inner side of the pipe wall through the piston shoes. The sliding disk in at least one radial fixing device can move back and forth relative to the main beam and is driven by a sliding disk air cylinder which is arranged on the main beam. The main beam is composed of a front half section and a rear half section which are independent from each other, and the front half section and the rear half section of the main beam are connected through a rotating assembly and can mutually rotate. The invention further discloses an overhauling method of the self-walking type pipeline inwall overhauling system, and the self-walking type pipeline inwall overhauling system can freely walk on the pipeline inwall and can achieve pipeline flaw detection, cutting and repairing.