The invention relates to a detection method and device of a distribution transformer winding material. The method comprises the steps of detecting whether the capacity of a distribution transformer is smaller than 500 kVA or not; if the capacity is smaller than 500 kVA, using a thermoelectric effect method to heat a distribution transformer winding to make the temperature difference of the two ends of the winding reach a set temperature; obtaining a thermoelectric potential value when the temperature difference reaches the set temperature; if the thermoelectric potential value is smaller than or equal to a first thermoelectric potential threshold value, determining that the material is copper; if the thermoelectric potential value is larger than or equal to a second thermoelectric potential threshold value, determining that the material is aluminum; if the thermoelectric potential value of the distribution transformer is larger than the first thermoelectric potential threshold value and smaller than the second thermoelectric potential threshold value or the capacity is larger than or equal to 500 kVA, using an inversion reckoning algorithm to determine the material of the winding. According to the detection method and device of the distribution transformer winding material, starting from the angle of the capacity of the distribution transformer and the thermoelectric potential value, the accuracy of the detection is drastically improved.