The invention discloses a special fixture for a flexible thin-wall bearing. The fixture comprises a parallel jaw, a free fixture body and a mounting shaft component; the mounting shaft component comprises a blind rivet, a bearing mounting body and flexible thin-wall bearing clamping devices; the bearing mounting body comprises a shaft-shaped main body; an oval journal is arranged at the front part of the shaft-shaped main body; a conical part is arranged at the back part of the shaft-shaped main body; the blind rivet is connected with the tail end of the conical part; the flexible thin-wall bearing clamping devices are arranged on two sides of the oval journal; the free fixture body comprises fixture support plates, fixtures and guide shafts; the fixture support plates comprise a movable fixture support plate and a static fixture support plate which are arranged symmetrically; the fixtures comprise a movable fixture and a static fixture which are arranged symmetrically; and the movable fixture and the static fixture are connected through the guide shafts to form an oval clamping hole through surrounding. With the fixture, the flexible thin-wall bearing is mounted in the oval journal of the bearing mounting body, and the problem that the round inner ring of the flexible thin-wall bearing and the oval journal of the bearing mounting body are not easy to assemble is solved.