A fast numerical algorithm for six degrees of freedom electromagnetic probing is proposed, to simulate magnetic field inside a space of 500 mm×500 mm×500 mm. Compared with strict algorithm and current-loop approximation algorithm, normalization computing time ratio is 10⁶:70:1. It shows that the algorithm is feasible and reliable. Finally, how to effectively minimize deviation caused by limited length effect of solenoid coil is discussed to further improve the probing precision and stability of the probing system.