As the wave impedance is significant discontinuous at the sheath cross bonding points of the cable, the reflection and refraction of traveling wave are extremely complicated, make it hard to identify the traveling wave reflection from the fault point or the end point of cable. By analyzing the characteristic of modal parameters, this paper give the criterion of fault type judgment and proposed a novel fault location scheme which using model four as fault location signal. The scheme solve the problem of wave front identify in traditional fault location methods due to the complicated reflection and refraction of traveling wave and also solve the problem of second reverse wave identification. A model of 220KV power cable system is built by ATP-EMTP, the simulation results show that the fault location scheme is feasible and has higher accuracy.