The invention relates to an automatic control system of a robot for cleaning oil sludge, sludge and the like in an oil storage tank, comprising a PLC part, a system for acquiring and displaying images in the tank, a combustible gas monitoring system, a robot walking system, an oil sludge cleaning, an oil sludge sucking control system and other parts. The automatic control system can realize the remote control outside the tank of the robot for cleaning the oil tank, has two modes of automatically cleaning the tank and manually cleaning the tank, and can be used for acquiring image information in the tank and displaying the image information, displaying the concentration of the combustible gas, realizing water jet and push shovel cleaning work, moving the robot and controlling the sucking of the oil sludge. The control system constructed by taking the PLC as the core has high automatic degree, is easy for expansion, librates workers for cleaning the tank from high-intensity work and severe dangerous environments, realizes the safety, the simpleness and reclamation for cleaning the tank and has remarkable social and economic benefits. The automatic control system can be also used for cleaning a finished product oil tank, an autoclave, a cooling tower, a storage tank and the like in the severe dangerous environment.