We present the results of a Damped Lyman α (DLA) system survey in the Dark Energy Spectroscopic Instrument (DESI) Survey Data release 1. The concordance DLA catalog combines the prediction from two fully automated techniques: the convolutional neural network (CNN) model and the Gaussian Process (GP) model. For each absorber, we obtain an accurate measurement of the redshift, the HI column density, and the equivalent width of associated metal absorption lines of the DLA absorbers. About 17,346 absorbers are identified and characterized in 27,974 quasar spectra with 2.1 < z < 5.8, S/N > 3, NHI > 1020 cm−2, out of which 7,884 have NHI > 2 × 1020 cm−2. We build the largest statistical sample by combining the DLA sample from SDSS DR16. The column density distribution function (CDDF) we obtained agrees with the spline model drawn from previous observations. With better estimating of the systematics from realistic mock data, we give a tight constraint on the incidence of DLA and the evolution of HI mass density at z > 2.
