The invention discloses an integrated self-locking mechanism for a sliding-block-type synchronizer. The integrated self-locking mechanism comprises a gear hub, a sliding gear sleeve, a combination gear ring, an inner friction ring, a friction middle ring, an outer friction ring and a self-locking packaging body component, wherein the sliding gear sleeve and the self-locking component are both arranged in a groove of the gear hub; and the sliding gear sleeve is arranged on the gear hub in a matched manner through an outer spline. According to the integrated self-locking mechanism, a sliding block, a pin and a spring of the self-locking mechanism are made into an integrated structure; during assembly, the packaging body component is arranged in the groove of the gear hub, so that assembly is simple and easy; meanwhile, for improving the strength of the gear hub, radial spring holes formed in the side part of the gear hub are omitted because the side part strength of the gear hub is weakened by the existence of the spring holes and the gear hub is easily fractured; after the spring holes are omitted, the gear hub cannot be fractured because the side part strength is too low; the strength of the gear hub is enhanced, and the torque transmission capacity of the synchronizer is improved; and the synchronizer can be applied to transmissions with large torques, so that a technical condition is provided for development of the large-torque transmissions.