Solid waste-derived belite-rich calcium sulfoaluminate (BRC) clinker was successfully synthesized, which incorporated incineration bottom ash, recycled concrete powder, and phosphogypsum as the feedstock. The mineral components of BRC clinker were predicted by theoretical formula and thermodynamic modelling, which aligned well with experiments. The effect of clinkering temperature on viscosity, Gibbs free energy, phase equilibrium, and real mineralogy was thoroughly investigated by thermodynamic predictions and experimental characterizations. Optimal clinkering at 1200 °C for 3 h yielded BRC clinker predominantly consisting of 46.3 wt% belite, 22.5 wt% ye'elimite, 16.6 wt% fluorellestadite, and 7.1 wt% brownmillerite. Hydrates AFt and amorphous (AH3 and C–S–H gel) formed the network, playing a crucial role in developing a 60 d paste strength of 42.2 MPa. Utilizing lower temperatures and low-carbon embodied solid wastes for producing this BRC clinker promised to reduce CO2 emissions and preserve natural resources.