Abstract: In this paper, the cable element with moving nodes is used to establish the dynamic equations of the driving cables within the cable-driven continuum robot (CDCR), and the driving cables can be modeled as constraint equations acting upon the CDCR system. Firstly, the transformation relationship between material description and spatial description is introduced. Subsequently, the elastic deformation virtual power of the driving cables is derived, assuming negligible cable mass flow. Theoretical findings demonstrate that when the driving rope maintains a consistently linear configuration, the virtual power equations derived from the material and spatial coordinates exhibit equivalence. At this juncture, the driving influence of the rope becomes equivalent to the constraint equation imposed by its length. Finally, the reciprocating driving process of CDCR system is studied by employing the proposed method and the driving force non-smooth hysteresis and backlash behavior induced by sliding friction are observed.