Abstract: The electromagnetic compatibility(EMC) design rationale is discussed in this paper, as well as the philosophy of the shielded cable's grounding. Several cable shielding methods are analyzed in this paper, focusing on their different shielding efficiencies and application conditions. The detailed technique about the overshield of the shielded cable bundle and the shortcoming of some methods commonly used in our country are discussed. An example is given to show how to use the cable shielding method and how to improve the equipment and system's electromagnetic compatibility.