The substitution of Ba2+ for Ca2+ in both dicalcium silicate (C2S) and ye'elimite (C4A3$) has the potential to stimulate the development of early hydration activity of high belite sulfoaluminate cement (HBSAC). To relieve the emission pressure of CO2 in the cement industry and promote the early compressive strength development of HBSAC, the C2S-C4A3$ binary system with different amounts of Ba2+ substitution for Ca2+ was synthesized and investigated in this study. The SEM-EDS and XRD test methods confirmed the stoichiometric composition of Ba-bearing C2S-C4A3$ binary systems. The results showed that Ba2+ tends to preferentially replace Ca2+ in C4A3$ compared to replacing Ca2+ in C2S, resulting in more substitution amount of Ba2+ in C4A3$ mineral, as the designed substitution amount of barium increased from 25 wt.% to 55 wt.%, the stoichiometric formula of Ba-bearing C2S was transformed from Ca1.66Ba0.34SiO4 to Ca1.45Ba0.55SiO4, and the stoichiometric formula of Ba-bearing C4A3$ was transformed from Ca2.29Ba1.71Al6SO16 to Ca0.86Ba3.14Al6SO16. While excessive amount of barium (more than 45 wt.%) resulted in the increased content of by-products, such as BaSO4 and BaAl2O4, as well as the formation of C3S. The hydration properties of each group of synthetic clinker were investigated, including compressive strength, qualitative and quantitative analyses of the hydration products, leaching solution environment, and micromorphological analysis. The hydration products including C-(A)-S-H and AH3, as well as hydroxide (Ca(OH)2 and Ba(OH)2·8H2O), which can be carbonated to form carbonates (BaCO3 and CaCO3) by CO2 in the air. As the substitution amount of Ba2+ increased from 25 wt. % to 35 wt. %, the hydration degree of Ba-bearing α′L-C2S was promoted in the early stage, and the presence of C3S may affected the increase of early hydration activity of Ba-bearing α′L-C2S, however, the hydration degree of α′L-C2S with the most amount doping of barium in A055 samples exhibited the highest hydration degree of 88.0 % after hydration for 90 days. The compressive strength of high belite C2S-C4A3$ binary system of 3-day displayed a rapid increase from 8.6 MPa to 16.1 MPa, with the amount of barium increased from 25 wt. % to 55 wt. %. The compressive strength of A025 and A035 after hydration for 90 days increased steadily, reaching 35.0 MPa and 34.0 MPa respectively. However, the compressive strength of hydrated A045 and A055 samples for 90 days deteriorated and even cracked seriously for the hydrated A055 sample, which was attributed to the formation of a large amount of Ba(OH)2·8H2O and BaCO3 by excessive barium amount, and leading to the expansion and broken of the matrix. Thus, the designed amount of barium substitution for calcium in the C2S-C4A3$ binary system should be controlled, for a higher content of barium more than 35 wt. % could be damage to the development of the long-term hydration strength of the clinker. These results provided a theoretical basis to make it possible for the large-scale application of activated HBSAC, devoted to the sustainable development of infrastructure.