The CEPC is expected to deliver huge statistics of Higgs & Z bosons, boosting our understanding to the Higgs boson and EWSB. To achieve this physics goal, the CEPC need a detector with excellent performance.

In this talk, we will briefly summarize the physics motivation of the CEPC and quantify the requirements on its Detector performance, which then served as a guide line for the detector design and optimization. We will demonstrate how the physics objects are reconstructed and measured at CEPC, and summarize the status and results of the Detector optimization at the CEPC.