The utility model discloses a forced oil cooling vertical-ring high gradient magnetic separator which comprises a lower field yoke, an upper field yoke and an excitation winding which are all arranged on a stander, the lower end of the lower field yoke is provided with a gangue box, a drive rotating shaft is arranged on an upper magnetic pole, a rotary ring is arranged on the drive rotating shaft, a magnetic medium box is arranged on the outer circumference of the rotary ring, two sides of the rotary ring are provided with a mine feeding device and an ore concentrate unloading device, the rotary ring is provided with a flushing device, the excitation winding is arranged in a winding box in which cooling oil is filled, the winding box is communicated with a forced recirculation cooler through an oil pipe, and the side face or the bottom of the gangue box is connected with palsating equipment. Because the excitation winding of the separator is always dipped in the cooling oil, the forced recirculation cooler is used for circulation cooling to enable the elevation of temperature of the winding to be in a reliable range, ensure the normal and stable work of the excitation winding and save a great deal of water resource, and the utility model is safe and reliable to use.