In this work, the lamellar precursor PLS-1 was successfully modified by acid treatment, intercalation and interlayer silylation. The layered precursor PLS-1 with CDO topological structure was synthesized using H-magadiite as silicon source and tetramethylammonium hydroxide (TMAOH) as template agent. After acid treatment to remove interlayer organic molecules, various OSDA were introduced between the layers, and the interlayer expanded intercalated materials were obtained. Intercalation can not only improve the crystallization degree of the sample, but also introduce larger organic molecules between the layers to increase the interlayer distance. 1,3-Dichlorotetramethyldisiloxane was used to silanize the intercalated material. The silanization conditions were investigated and the best conditions were obtained. Through the construction of the theoretical model, the experimental data were compared to show that the new molecular sieve PLS-1-2Si material has a 12 × 12-R interlayer expanded structure.