The Faraday shield (FS) is a key part of the radio frequency (RF) ion source for high power neutral beam injection system. The RF transfer efficiency and power loss ratio of the driver with two different types of FS are analyzed using a finite element model. These two types of FS are divided into inclined shape slits and Z shape slits, and each slit shape can be subdivided into six types. It is found that the change of the slit shape on the FS has little effect on the RF transfer efficiency and the power loss ratio. For the six drivers with inclined shape FS slit, the difference in RF efficiency between them does not exceed 1%, and the difference in the power loss ratio on the FS does not exceed 1.2%; for the six drivers with Z shape FS slit, the change in the RF efficiency does not exceed 0.3%, and the change in power loss ratio on the FS does not exceed 0.4%. Meanwhile, taking electrons as the research object, the interception ability of 12 kinds of FS to particles was compared, and the optimal structure of the FS slit is determined.