Energy Non-linearity study at Daya Bay

The Daya Bay Reactor Neutrino Experiment has measured a non-zero value of the neutrino mixing angle $\theta_{13}$ with a significance of 7.7 standard deviations by a rate-only a nalysis. The distortion of neutrino energy spectrum carries additional oscillation information and can improve the sensitivity of $\theta_{13}$ as well as measure neutrino mass splitting $\Delta m^{2}$ . A rate plus shape analysis is performed and the results have been released in August at NuFact 2013. Detector energy non-linearity response study is crucial for the rate plus shape analysis. In this contribution, We present A brief description of energy non-linearity study at Daya Bay.