Abstract: For the 3D printing process of slurry direct writing ceramics with single screw extrusion structure, lead lanthanum zirconate titanate (PLZT) ceramic slurries with different solid content (60%, 70%, 75%, volume fraction) were prepared, and the effect of solid content on the slurry flow performance in screw groove was studied by MRT LBM method. The results show that the three ceramic slurries all showed obvious non-Newtonian fluid characteristics of shear thinning. MRT LBM method could effectively realize the flow simulation of ceramic slurries during 3D printing. With the increase of solid content, the slurry flow speed decreased. In the case of ensuring that the slurry rheology met the printing requirements, the solid content should not be too high.