The utility model relates to a vehicle-mounted drilling fluid fixed control system which belongs to the technical field of petroleum drilling facilities, comprises a drilling liquid circulation tank and is characterized in that: the drilling liquid circulation tank comprises a walking base on which a tank body is fixed; a hydraulic landing leg is arranged at the front end of the walking base; and a wheel is arranged at the rear end of the walking base. The vehicle-mounted drilling fluid fixed control system has all functions of the conventional drilling liquid circulation tank, has a compact structure and novel design and can directly drag the drilling liquid tank to a new well position under the traction of a traction truck; therefore, quick transportation and positioning of the drilling fluid fixed control system can be realized.