The technological process of polymer nanoporous antireflection film fabrication is discussed in detail. And the effects of molecular weight of the polymer, experimental temperature, humidity and the volatility of common solvent on the polymer nanoporous antireflection film are also analyzed. Larger polymer's molecular weight, lower condition temperature, higher relative humidity and lower solvent's volatility will lead to increasing the porous size and the scattering loss. So the transmission ratio of the film will be decreased. Lower molecular weight polymer (<15 kg/mol), higher temperature (>25 ℃), relative humidity lower than 30%， and lower boiling point solvent such as tetrahydrofuran are the key points for a small porous size and high transmission ratio.