Desiccation cracks exhibit a hysteresis behavior, referred to as crack dynamic hysteresis (CDH), where they display different geometric characteristics during the drying and wetting phases at constant soil water content. CDH has a complex effect on slope stability, an aspect often overlooked in analytical and numerical methods. In this study, we conducted experimental and numerical analyses to provide new insights into the effects of CDH on slope stability. A series of laboratory experiments on desiccation cracking under D-W cycles were performed. The testing results were used to develop and validate an extended dynamic dual-permeability model (DDPM). The proposed DDPM was integrated into a set of slope stability analyses using the finite element method. The numerical model findings show that CDH causes greater fluctuations in crack dynamics and increases soil water retention under D-W cycles. Neglecting CDH leads to underestimations of slope stability during dry conditions and overestimations during wet conditions.