With ethylene glycol monovinyl ether (EPEG) as the major monomer, acrylic acid (AA) as the minor monomer, and 2- hydroxyethyl methacrylate (HEMAP) or blocked amide phosphate (CAP) as the functional monomer, two EPEG mud-resistant polycarboxylate superplasticizers PCE-EP1 and PCE-EP2 were synthesized by free radical copolymer-ization in aqueous solution. The structure of superplasticizer was characterized by FTIR and 1HNMR. The dispersion and anti-mud performance of the synthesized superplasticizer to cement were tested by the fluidity of cement paste. Combined with XRD and XPS, the interaction mechanism between superplasticizer and cement and montmorillonite was explored. The results show that when the dosage of superplasticizer is 0.2% and the dosage of montmorillonite is 2%, PCE-EP1 and PCE-EP2 have certain mud resistance. XRD shows that the water reducing agents PCE-EP1 and PCE-EP1 have no intercalation adsorption on montmorillonite, thus improving the dispersing ability of the water reducing agent to soil.