The invention relates to a rapid-assembling and dissembling split clamp used for fatigue test, and belongs to the field of material performance test. The split clamp is used for testing the tensile fatigue life of a metal material. Fatigue life test of a component or material is needed to improve the reliability of a part and enhance the safety of a machine device. In the practical test process, inconsistence of the practical bearing load and the design load of the test piece, caused by errors existing in the test piece processing and clamping process and extra load possibly generated in the test process, has influences on the test precision. The test piece fatigue life test clamp is provided to solve the above problem, adopts split design, has centering self-adaptability, and can effectively solve the centering error in the clamping process; and when test piece is replaced, dismounting of a clamp body is not needed, the test piece clamping is fast, the centering precision is consistent, the workload of centering detection is reduced, and the test process is accelerated.