In order to reduce the carbon emission and embodied energy consumption in the production process of ultra-high performance concrete (UHPC), ultra-high performance alkali-activated concrete (UHPAAC) was prepared by replacing traditional Portland cement with alkali-activated slag materials, and the effects of sodium silicate modulus (1.1, 1.3, 1.5) and alkali equivalent (6%, 7%, 8%, mass fraction) on the workability, mechanical performance and durability performance of UHPAAC were studied, and the environmental benefits were analyzed. The results show that the pore structure of UHPAAC can be refined by appropriately increasing the sodium silicate modulus and alkali equivalent, and the properties of UHPAAC can be improved. UHPAAC has a faster coagulation hardening and lower fluidity than UHPC. UHPAAC has high early strength, and the compressive strength of standard curing 7 d exceeds 100 MPa, and reaches 80.2%~92.4% of the compressive strength of 28 d. The capillary water absorption mass and water absorption of UHPAAC are significantly higher than those of UHPC, but the chloride ion permeation resistance is better than that of UHPC, and the carbonization depth is 0 mm after 28 d of carbonization under accelerated laboratory conditions. In addition, UHPAAC can significantly reduce carbon emission and embodied energy consumption. This study indicates that when the sodium silicate modulus is 1.5 and the alkali equivalent is 6%, the comprehensive performance of UHPAAC is optimal and its environmental impact is minimal.