The utility model provides a mobile liquid storage device, which relates to the technical field of liquid storage, and comprises a box body mechanism, a liquid level detection device, a control device, a liquid inlet device and a mobile cart, the box body mechanism is arranged on the movable cart and is connected with the movable cart; the liquid level detection device is connected with the box body mechanism, the liquid level detection device is electrically connected with the control device, and the control device is electrically connected with the liquid inlet device; the liquid level detection device is used for detecting water level height information in the box body mechanism and transmitting the water level height information into the control device, a water level height threshold value is set in the control device to correspondingly control opening or closing of the liquid inlet device, and the technical problems that a common liquid storage device is inconvenient to move and low in recycling efficiency are solved; the technical effects that the liquid storage device is convenient to move, high in recycling efficiency and high in operability are achieved.