This paper present a new power flow calculation method, it can quickly and exactly solve the power flow problem in the radial or mesh type power system, including those with PV bus systems. This kind of method is to turn the slack bus voltage and the load power to the equivalent current sources, and direct calculate the bus voltage quickly and exactly. After testing at radial, mesh, radial with PV bus, and mesh with PV bus, 4 different type power systems, the results are all match those results of reference. Since the simplicity and easy programming this method would match the need of power flow calculation.