Superconducting cables made of the high temperature superconducting tapes have broad application prospects. Among them, the conductor on round core (CORC) cable is an ideal cable for manufacturing nuclear fusion magnets due to its low AC losses and good mechanical properties. However, the existing technology is difficult to achieve that the joint resistances of the CORC cables are exactly same, which will have an important influence on the electro-magnetic properties of the CORC cables. Therefore, the 3D finite element model of the CORC cables considering joint resistances is established and the impact of joint resistances on the AC loss and the current distribution of the CORC cables is analyzed. This work has a significant guide for the manufacture of CORC cables.