To explore the relationships among fertility stress, dyadic coping and marital quality in couples undergoing in vitro fertilization-embryo transfer (IVF-ET). Couples receiving IVF-ET treatment at the clinic of the reproductive medicine centre of a hospital in China from February 2023 to October 2023 were selected by convenience sampling. A general information questionnaire, the Infertility Fertility Stress Scale (COMP-FPSS-SF), the dyadic coping inventory, and the marital adjustment test were used to evaluate the results. AMOS24.0 software was used to construct an actor-partner interdependence model that extended to mediation to analyze the relationships among couples' fertility stress, dyadic coping, and marital quality. The fertility stress level of IVF-ET wives was significantly higher than that of their husbands (p<0.05). Wives' levels of dyadic coping and marital quality were significantly lower than those of husbands (p<0.05). Fertility stress, dyadic coping, and marital quality were positively correlated between IVF-ET couples (p<0.01). In terms of the actor effect, the fertility stress of IVF-ET couples had a significant impact on their marital quality through their dyadic coping (β=-0.188, p<0.05; β=-0.109, p<0.05). In terms of partner effects, wives' fertility stress significantly affected their husbands' marital quality through their own or their husbands' dyadic coping (β=-0.055, p<0.01; β=0.157, p<0.01). Dyadic coping mediates the relationship between fertility stress and marital quality in IVF-ET couples. Nurses can use husbands and wives as central individuals and dyadic coping as the starting point to formulate intervention measures to reduce fertility stress and improve marital quality.