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The evolution mechanism behind low cycle fatigue crack propagation behavior subject to overload was investigated by experimental and numerical methods. The retardation effect after the overload application was investigated by using compact tension (CT) specimens. An analysis model was established to consider accumulative plastic damage for CT specimen under single tensile overload. An elastic-plastic numerical model is established, and the stress-strain field near the crack tip is quantified by different numerical parameters. The crack opening displacement was got to reflect the influence of overload on plasticity-induced crack closure, and the evolution mechanism and accumulative plastic damage were investigated by exploring the residual compressive stress near the crack tip. The results show that the residual compressive stress produced by the tensile overload has great influence on the retardation effect, and the large plastic deformation near the crack front region after an overload witnesses a more significant crack closure phenomenon. The magnitude of residual compressive stress near crack tip increases with the increasing overload ratio, that sharpens the retardation effect after single tensile overload. [ABSTRACT FROM AUTHOR]