Aiming at the problems of long construction time and easy shrinkage cracking of pavement base, the slow-setting and expansive cement (SEC) was prepared using circulating fluidized bed ash and slag (CFBA and CFBS), S95 ground granulated blast furnace slag (GGBFS), and silica fume (SF) as supplementary cementitious material in this paper. By adjusting the content of supplementary cementitious material, the ratio of ash and slag, the performance of SEC was evaluated by the indexes of water consumption of standard consistency, setting time, flexural and compressive strength. The hydration products of mortar samples and the influence mechanism were studied by means of XRD, TG-DTG, FTIR, and SEM-EDS. The results showed that when the SF content was 6 %, the compressive strength of the mortar specimens reached its maximum (35.19 MPa) at 28 days, which increased by 23.04 % compared to the control group. Meanwhile, the free calcium oxide and gypsum in CFBA reacted under alkaline conditions to form ettringite (AFt) and C-S-H gel, which caused the volume expansion of cement and led to a decrease in shrinkage within the cement system. SEC has higher mechanical properties and much smaller shrinkage cracks than ordinary cement. Therefore, replacing part of the cement by solid waste such as CFBS to prepare SEC to compensate for the shrinkage of the pavement base is an effective way to reduce pavement cracking.