The invention provides a brake spanner positioning mechanism of a fishing reel. The mechanism comprises a brake spanner, a spanner handle, two clamp pins, a release hole and a release button, wherein the clamp pins are sleeved in a clamp pin spring and located in two positioning holes of a fishing reel main body; the end of each clamp pin protruding out of each positioning hole is a spherical body; the release hole is formed in the position of the spanner handle corresponding to each clamp pin; the release hole is a through hole and is divided into a big hole area and a small hole area by a step inside; the big hole area faces to one end of each clamp pin; the outer edge of the big hole area is provided with two inclined planes for pressing the clamp pins into the positioning holes; and the release button is arranged in the small hole area. In the invention, the positions of the clamp pins are adjusted to avoid the damage to the appearance when in use, thus the service life of the product is prolonged.