Abstract: The external energy that enters the slotted cavity through the penetrative wire will generate the induction current on the MSL. The coupling damage to sensitive device is increased. The model of the shield cavity with penetrative wire and PCB are established. The coupling calculations are carried out by multi angles. After validating the model validity,the corresponding current variation law due to the parameter variations such as the different PCB models, the different termination resistances, the wire radius, the connection between the wire and the cavity wall and the multi wires are discussed by the finite element method. The results show: the effect for field of the double medium model is closer to the actual PCB structure; the impedance matching with MSL can't be considered under the condition of little resistance difference, the resistance may not be equal. The current will increase when the wire radius becomes large. The current when the wire is connected with the different cavity surface are much higher than non contact situation, and they will inspire the new resonance points. The current of the multi wires is higher than the single case, it has the same effect when the line spacing changes. It is more obvious especially before the first resonance;The resonance position will not be affected by multi wires.