Abstract: New continuous cable traction power supply system（CCTPSS） pattern is one of the method to reduce（or cancel） electrical phase separation that exists in traction network, but step power supply scheme makes cable traction network（CTN） structure complicated. In order to study CCTPSS operation characteristics, two-port network analytic theory was utilized, and CTN was decomposed into three kinds of sub-network: traction cable, catenary-rail, and traction transformer. Uniform CCTPSS calculation model was built to calculate node voltage and branch current through node voltage splitting method, then CCTPSS operation characteristics were obtained. At fundamental frequency, CTN voltage change and traction transformer current distribution relationship of one case system were analyzed under different work conditions. At harmonic frequency, high frequency harmonic transmission problem was researched. Compared with existing traction power supply system, it is found that voltage loss of CCTPSS is smaller, utilization rate of regenerative energy is higher, the harmonic amplification effect in central substation is weaker, and the service performance of new system is more superior.