Fault calculation is the basic computation in power system. With the increasing node number and covering area of power grids, it takes much more time to calculatethan ever. Calculation and analysis is facing serious challenges, traditional serial computing methods have been unlikely obtain substantial progress on computing speed, muti-core parallel computing is leading software development. The technology of OpenMP-Based Parallel Computation is introduced. The basicSprinciple and model of Sfault calculation is analyzed. Using serial and parallel ways seperately to calculate the time for fault testing. Simulation results show that the time was significantly lower than the serial parallel computing, through the experiment validity of the method is tested.