The invention relates to a main transformer oil flow guide microcirculation device and a using method. The main transformer oil flow guide microcirculation device comprises a main transformer body and radiators arranged on the two sides of the main transformer body. The using method of the main transformer oil flow guide microcirculation device is further provided. Oil flow guide spraying pipes are arranged below a winding and an iron core in the main transformer body, the two lateral walls of the upper portion of the main transformer body are provided with oil outlet valves, the oil outlet valves are connected with inlets of the radiators on the two sides respectively through pipes, outlets of the radiators are connected with the oil flow guide spraying pipes through oil return pipes, the oil return pipes are provided with an oil inlet valve and a frequency conversion microcirculation pump, the frequency conversion microcirculation pump drives an oil way to conduct circulation, the sides, facing the winding and the iron core, of the oil flow guide spraying pipes are provided with oil outlet holes respectively, and the ends of the oil flow guide spraying pipes are closed. By means of the main transformer oil flow guide microcirculation device, shortcomings of an existing main transformer oil flow microcirculation mode are overcome, the frequency conversion microcirculation pump controls small holes to conduct small-amount spraying, the main transformer winding and the iron core are cooled in a concentrated mode, and the cooling effect is strengthened; meanwhile, turbulence and bubbles are avoided, and the cooling efficiency and the safety performance are effectively improved.