This is the official dataset of TianXing-S2S, providing 51-member global daily-mean ensemble forecasts up to 45 days at 1.5° resolution. For convenience, we currently display one forecast sample per month from 2018 to 2021, aligned with the ECMWF S2S initialization schedule. Each sample includes 21 variables: Q, T, U, V, and Z at 200, 500, and 850 hPa, along with t2m, tp, olr, mslp, u10, and v10. The complete test set samples and source code will be uploaded upon acceptance of our manuscript.