The Daya Bay experiment was designed to measure the neutrino mixing angle $\sin^{2}(2\theta_{13})$ with unprecedented precision through a relative measurement with eight functionally identical electron anti-neutrino detectors deployed at three experimental halls near three high-power nuclear reactor complexes in south China. In March 2012, the Daya Bay experiment discovered the non-zero value of $\sin^{2}(2\theta_{13})$ with $5.1\sigma$ significance with 55 days data taking with partially installed six electron anti-neutrino detectors. After that, Daya Bay experiment installed the remaining two detectors in the summer of 2012. With 1230 days of data-taking since December 2011, the Daya Bay experiment has accumulated more than 2.5 million reactor electron anti-neutrino inverse-beta-decay events, hence obtained the most precise measurement of $\sin^{2}2\theta_{13} = 0.0841 \pm 0.0033$ and effective mass-squared difference $|\Delta m^{2}_{ee}|= (2.50 \pm 0.08) \times 10^{-3}\ {\rm eV}^2$ up to date.