Abstract: To promote coordinated development of the ecological environment and the building materials industry, this study proposed an innovative approach to use CaSO₄ and CaCl₂ in synergy with cement to solidify sintered sludge, creating an environmentally friendly green concrete. The comprehensive effects of CaSO₄ and CaCl₂ on the macroscopic properties, microstructure, economic and environmental benefits of sintered sludge-cement concrete were systematically explored. The results showed that the addition of CaSO₄ and CaCl₂ significantly improves the mechanical properties of the concrete, especially when they were combined, the compressive, flexural, and splitting strengths can be increased by 46.96%, 34.38% and 48.46%, respectively. In terms of frost resistance, the combined addition of both significantly reduced the loss of mass and relative dynamic modulus of elasticity during freeze-thaw cycles, with reductions of up to 62.63% and 93.32%, respectively, increasing the maximum number of freeze-thaw cycles by 25 times. The synergistic use of CaSO₄ and CaCl₂ transformed the microstructure of the sintered sludge-cement paste from loose and porous to dense and compact, which was the result of combination of calcium aluminate expansion and Friedel's salt filling the pore structure. Moreover, the cost and carbon emissions per unit strength provided by the mentioned concrete were reduced by 20.86% and 21.81%, respectively, making it a promising green high-performance building material.