Abstract: Aiming at the accuracy of the signal-in-space after BeiDou-3 (BDS-3) is officially opened, The paper selected one-year Global Navigation Satellite System (GNSS) mixed broadcast ephemeris data (from August 1st, 2020 to July 31st, 2021) and used the precision orbit and clock offset provided by the German Potsdam Geoscience Research Center (GFZ) and International Global Navigation Satellite System Service (IGS) data center of Wuhan as reference to evaluate the accuracy of the BDS-3 signal-in-space. The research showed the orbit accuracy of the BDS-3 is better than 0.100 m, 0.405 m, and 0.547 m in the radial, along-track, and cross-track respectively, and the clock error accuracy is better than 1.926 ns, and SISRE statistical accuracy only affected by the orbit error is 0.134 m, and signal-in-space range error (SISRE) statistical accuracy is 0.612 m. SISRE of the geostationary orbit (GEO) satellites is 1.137 m. Compared with the GEO satellites, and SISRE of the inclined geosynchronous orbit (IGSO) satellites and the medium earth orbit (MEO) satellites are reduced by 36.3% and 51.3% respectively.