The invention discloses an outdoor liquid storage tank. The outdoor liquid storage tank is characterized in that a nitrogen pipeline 2 is arranged on the side surface of the upper portion of a tank body in a communicating mode, a nitrogen sealing valve is arranged on the nitrogen pipeline 2 and is connected to an outlet of a nitrogen tank through a pressure reducing valve, the top of the tank bodyis provided with a ventilation elbow, a one-way exhalation valve is arranged at the ventilation elbow, an oil inlet is connected with an oil pipe penetrating through a nitrogen sealing layer, the lower end of a manual oil pouring opening is connected to an oil liquid isolation area, the oil liquid isolation area penetrates through the nitrogen sealing layer to communicate to the bottom of the tank body, a liquid pressure release valve is arranged on the side wall of the bottom of the oil liquid isolation area 6, the upper portion of the oil liquid isolation area is provided with a one-way airvalve communicating with the nitrogen sealing layer, the manual oil pouring opening is covered by a sealing cover with the one-way air valve, an oil outlet is formed in the side face of the lower portion of the tank body, and a stop valve is arranged at the end portion of the oil outlet. According to the outdoor liquid storage tank, leakage can be prevented, a liquid can be cooled, normal air pressure in the tank body can be maintained, and the safety of the outdoor liquid storage tank is greatly improved.