Abstract
This thesis we presented the design study for building a semi-nondestructive undulator photon beam position and profile monitor. It is a mesh wire monitor. However, in order to be classified as a semi-nondestructive monitor, the destruction to the undulator photon beam have to be minimized under the constrains of the required position resolution. We first used a gaussian beam to simulate the undutator light. That is just for simplicity. Finally, we should use the known photon beam profiles (both the undulator light and the bending synchrotron light) to fit the precise position of the undulator photon beam. For now, we have completed the design of mesh wire monitor and electronic system.