To minimize the costs of transporting and disposing of the muck from slurry shield tunneling in silty clay formation, the feasibility of using the muck from slurry shield tunneling in silty clay formation to replace bentonite in the preparation of synchronous grouting slurry is investigated through uniformity tests and theoretical analyses. The research results reveal the following: (1) When the main components of the muck from slurry shield tunneling in this type of formation are similar to those of bentonite, it is largely feasible to employ the muck to completely replace bentonite and partially substitute sand for the configuration of synchronous grouting slurry in terms of both slurry performance and economic benefits. (2) In the single-factor influence analysis, compared with the soil-to-binder ratio, the binder-to-sand ratio has a more pronounced impact on the density, setting time, and fluidity of the slurry, while the water-to-binder ratio has a more significant influence on the consistency, bleeding rate, and strength of the slurry. (3) The larger the amount of muck incorporated, the higher the contents of montmorillonite and clay particles in the slurry, leading to an increase in slurry density, a reduction in setting time, a decrease in fluidity, and an improvement in strength. (4) In the analysis of the interaction effects of various factors, the factors that have relatively significant interaction effects on the density, consistency, bleeding rate, setting time, fluidity, and 28-day compressive strength of the slurry are the soil-to-binder ratio and the water-reducing admixture, the binder-to-sand ratio and the soil-to-binder ratio, the fly ash-cement ratio and the binder-to-sand, the fly ash-to-cement ratio and the binder-to-sand ratio, the binder-to-sand ratio and the water-reducing admixture, respectively. (5) Determining the contents of montmorillonite, clay particles, and sand in the muck and the level ranges of each factor is crucial for the successful configuration of such slurries.