Abstract: In view of the pulsed eddy current flaw detection of ferromagnetic and non ferromagnetic metals, the numerical simulation models of pulsed eddy current testing under the magnetic shielding were established. The distribution of magnetic induction line and the mechanism of action of eddy current testing signal were researched. Magnetic shielding included: magnetic shielding within the coil, magnetic shielding outside the coil, magnetic shielding both inside and outside the coil. The simulation results show that magnetic shielding in the inner magnetic shielding of the coil can most effectively improve the sensitivity of defect detection for the ferromagnetic and non ferromagnetic metal in the four magnetic shielding models.