The invention provides a transition section surface hardness treatment method of a turnout tongue rail end of a steel rail applied to the technical field of production of steel rails. The transition section surface (2) hardness treatment method of a rail end (1) comprises the following treatment steps: 1) a rail end raw material for machining the rail end (1) is heated to a temperature section of 1050-1250 DEG C; 2) the air-blast quenching treatment is performed for the heated rail end raw material; the wind pressure of air-blast quenching is 0.20-0.35 Mpa; and the natural cooling is performed after the air-blast quenching treatment is performed to reach 400-450 DEG C; and 3) the rail end raw material is naturally cooled to form the rail end (1). The treatment method is simple in process, can effectively increase the transition section surface hardness of the turnout tongue rail end, cannot generate worn pits caused by wheels passing through the steel rail in use, needs no frequent replacement of a turnout tongue rail, and reduces the production cost and the maintenance cost of the steel rail.