The invention relates to the technical field of relevant devices for oil storage of power plants and discloses a deep buried type cooling device for an oil storage tank of a power plant. The deep buried type cooling device for the oil storage tank of the power plant comprises a tank body, an oil guiding connector, a funnel-shaped flow guiding mechanism, an external flow guiding mechanism, inward grooves, an insulated heat-conducting plate, a heat supply supporting mechanism, four return pipes, a circulation guide pipe, a circulation pump, a slag filtering mechanism, four connection rods, an internal flow guiding mechanism, a temperature sensor, a control panel, an exhaust pipe and a pressure release valve. The oil guiding connector is installed in the middle of the top of the tank body. The funnel-shaped flow guide mechanism is installed on the top of the outer side of the tank body. The external flow guiding mechanism is installed outside the tank body. The deep buried type cooling device for the oil storage tank of the power plant effectively absorbs heat given out by the tank body, greatly reduces the amount of led-in cooling water, reduces the consumption of an equipment cooling energy source, changes a traditional manner of directly conducting sprinkling on the oil tank, avoids sprinkling area omission and conducts covering cooling on the surface of the outer side wall ofthe tank body to the maximum extent.