Abstract Electromagnetic field analysis of YBCO coated conductors with large cross-sectional aspect ratio exposed to the non-uniform magnetic field in superconducting power cables was carried out. We calculated the non-uniform magnetic fields of one- and two-layer superconducting power cables to which an YBCO coated conductor was exposed. The electromagnetic field associated with the YBCO coated conductor carrying an AC transport current in such non-uniform magnetic fields was calculated using a numerical model that employed finite element method (FEM) for estimating the AC loss. The AC loss of the superconducting power cables was determined by the sum of the AC losses of the conductors. The numerically calculated AC losses were compared with the analytical values.