AbstractWe report the fabrication of a corrosion‐resistant and room‐temperature curing composite latex coating with simple and environmentally friendly characteristics. Poly(vinylidene chloride) (PVDC) seed latex was first synthesized by emulsion polymerization of vinylidene chloride (VDC) monomers, subsequently the core‐shell structure of PVDC/poly(chlorotrifluoroethylene‐co‐methyl methacrylate‐co‐butyl acrylate) (PVDC/PCMB) particles were prepared via seeded emulsion copolymerization of PVDC seed particles with chlorotrifluoroethylene (CTFE), methyl methacrylate (MMA), and butyl acrylate (BA) comonomers. Furthermore, the PVDC/PCMB composite waterborne coating was smoothly fabricated. Besides, the film‐forming and anticorrosive performances could be improved by adjusting the feed ratio of acrylate comonomers in the shell layer and the core‐shell ratio, which was attributed to the synergistic effect of the low‐temperature curing PCMB nanodomains and the anticorrosive PVDC nanodomains. Moreover, the PVDC/PCMB coating still showed the outstanding corrosion resistance even after immersion in 3.5 wt% NaCl solution for 400 h.