Porous nano-structured vanadium dioxide (VO2) thin films have been prepared on mica substrates via sol–gel process using surfactant cetyltrimethyl ammonium bromide, nonionic surfactant polyethylene glycol, and anionic surfactant sodium dodecyl sulfate as nano-structure directing agents. Models concerning the structure forming were proposed to explain the synthesis mechanisms between V2O5 colloid and different surfactants. Porous nano-structured VO2 films with sphere-shaped, island-shaped and strip-shaped nanocrystals are synthesized in the experiments, and the optical properties and thermochromic properties of these films are compared. The porous nano-structured VO2 films showed excellent infrared transmittance (nearly 70 %), low transition temperature (59.7 °C without doping), wide hysteresis width (37.8 °C), and different optical transmittance difference before and after the phase transition (39–67 %). The results suggest that these porous nano-structured VO2 films have significant importance in practical application in VO2-based optical and electronic devices.