An interfacial imperfection coupling model is proposed to characterize the imperfect interface in a bi-layered multiferroic cylinder by extending the generalized linear spring model of the uncoupled imperfect interface. Based on the model, fracture analysis is performed on the multiferroic cylinder containing intra-layer cracks. Parametric studies on the stress intensity factor (SIF) yield three main conclusions: (a) the mechanical imperfection can enhance the SIF independently; (b) the magnetic or electric imperfection can reduce the SIF only through its coupling with the mechanical imperfection; and (c) the magneto-electric imperfection coupling does not affect the SIF in any case.