AbstractDue to its high refractive index, photocatalytic activity, and photoinduced superhydrophilicity, TiO2 has advantages in photonic crystals (PCs). However, the composite of TiO2 and PCs needs to be calcined at high temperatures, and the structural stability of the composites is poor. In this study, photoinduced superhydrophilic TiO2–poly(hydroxyethyl acrylate)/polystyrene (PHEA/PS) PC composites with strong structural colors and self‐cleaning are fabricated by coating triethanolamine‐modified anatase TiO2 nanoparticles‐hydroxyethyl acrylate on the surface of PS PCs. The ordered arrays can be retained after the superficial layers of PS PCs are filled with TiO2–PHEA, and vivid blue, green, and red composites can be obtained. The water contact angles of the composites can be reduced to 3° in 0.4 s, and superhydrophilicity can be maintained for 180 days in a laboratory environment. The declining superhydrophilicity can be restored under UV irradiation. The composites can degrade the adsorbed methylene blue under UV irradiation. Photocatalytic activity and superhydrophilicity impart self‐cleaning ability on the composites. The locking of PS arrays by TiO2–PHEA enhances the structural stability of the composites, making them resistant to water soaking and washing. Therefore, the composites show prospects for decoration, fabric coloring, and wearable electronic devices.