A safety belt buckle includes a base unit, a driving unit mounted on the base unit, and a torque device mounted on the driving unit. The base unit is provided with a plurality of insertion slots, a rotation shaft, and a positioning portion. The driving unit includes a circular cap and a driving handle. The torque device includes a ring, two balls, two compression springs and a fixed plate. In practice, when the driving handle is driven by a user, the circular cap is rotated to operate the two compression springs which press the two balls to increase a resistance to the circular cap, and to obstruct rotation of the driving unit, thereby preventing the driving unit from being driven freely by an external force.