The application performance of ceramic slurry blended with modified sodium lignosulfonate GCL3S was studied, and results showed that GCL3S could obviously improve the dispersion and stability performance of the ceramic slurry. When the addition amount of GCL3S-1 is 0.3%, with the outflow time 41.79 s and thickening degree 1.37, the mass fraction of ceramic slurry could reach 71.26%. With the increase of molecular weight, the performance of ceramic slurry was improved firstly and then decreased. GCL3S-2 with Mw about 27700 had the best dispersion and stability performance of the ceramic slurry. When incorporated with sodium silicate, sodium hexametaphosphate, sodium pyrophosphate and sodium tripolyphosphate respectively, GCL3S-1 could further improve the dispersion performance of ceramic slurry. The outflow time of ceramic slurry was only 38.81 s when the mass ratio of GCL3S-1 to sodium hexametaphosphate was 1:1and the total addition amount was 0.2%. It means that the dispersion performance of this composite dispersant was significantly better than that of common inorganic dispersants.