Intercalation is usually achieved through the insertion of guest species into a pre-formed layered compound. Herein, we report our exploration of the formation of intercalation compounds through a direct growth method using cationic layered double hydroxide (LDH) and anionic polyelectrolytes. LDH precursors and intercalant molecules were used as the raw materials to directly grow layered intercalation compounds through a hydrothermal method. Three poly(sodium 4-styrene-sulfonate) (PSSNa) with different molecular weights (i.e., 70000, 200000, and 500000) were systematically studied as an intercalant in terms of their effect on the growth of intercalation compounds. The mass ratio of PSSNa and LDH was also varied to study how the formulation ratio of the raw materials influences the growth of the PSSNa/LDH intercalation compounds. These directly synthesized PSSNa/LDH intercalation compounds were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy, based on which their growth mechanism was discussed. This direct growth method offers an alternative for large-scale production of intercalation compounds for potential commercial applications.