In this paper, a new topology of parallel hybrid excitation machine (PHEM) with rated power of 500kW is proposed and analyzed. The proposed PHEM axially combines a permanent magnet synchronous machine (PMSM) with a brushless field excitation machine (BFEM), thus inheriting the advantages of the two machines, i.e. the high power density of PMSM and the field-regulating capability of BFEM. First, the configuration and operation principle of the PHEM are analyzed. Then, the performances, including no-load, rated-load and short-circuit fault, of the first axial part (i.e. the PMSM) and the second axial part (i.e. the BFEM) are investigated by 2D and 3D finite element analysis (FEA), respectively. Also, the overall performances of the PHEM are predicted and analyzed. Finally, a prototype of the 500kW PHEM is built and tested. The experimental results have verified the theoretical analyses of the PHEM.