Disclosed are a reliability test fixture and an online test device for a flexible display component. The fixture comprises a support and a rotating shaft rotatably mounted on the support. An engagement recess for fixing a flexible display component is provided in an axial direction on the surface of the rotating shaft. A test module used to detect an electrical parameter of an internal circuit of the flexible display component is disposed inside the rotating shaft. The test module has a test contact for electrically connecting to the flexible display component. During a test, the flexible display component is fixed in the engagement recess and is electrically connected to the test module.