The invention relates to a winding inter-pancake thermal resistance experimental measuring device based on distributed optical fiber temperature measurement for an oil-immersed transformer and a usingmethod thereof. In the invention, simulation windings are arranged in three layers of upper and lower layers in order to form a three-pancake simulation winding, each two layers of the simulation windings are separated by spacers and the gaps in the middle are filled with transformer oil, the uppermost and lowermost parts of the three-pancake simulation winding are respectively provided with heatsinks, the outer sides of the heat sinks and the simulation windings are wrapped with heat-resistant plates, heat-resistant wires are introduced into the copper tubes of the lower and middle windingsin the three-pancake simulation winding for heating, distributed temperature measuring fibers are introduced into the copper tubes of the three-pancake simulation winding for temperature measurement,and one ends of the distributed temperature measuring fibers are connected to a DTS demodulation system and transfer acquired signals to a PC end that is connected thereto via a bus by the DTS demodulation system. The device and method can obtain the data of winding inter-pancake thermal resistance through experimental means, which provides data support for hot spot analysis of transformer windings.