Chitosan microporous membranes were prepared by different pore-forming methods with chitosan as substrate and applied to the preservation of cherry tomatoes. The microstructure of the film was studied by scanning electron microscope, infra-red spectrum and optical microscope. At the same time, the properties and fresh-keeping effect of the film were evaluated. The results showed that the microporous membrane with good performance could be obtained by adding nano-ZnO, polyethylene glycol or nitrogen into chitosan. The air permeability coefficient of washed porous membrane with 4% of mass fraction nano zinc oxide was 37.90×10-15 cm3·cm/(cm2·s·Pa), which was close to the air permeability coefficient of PE fresh-keeping film, while its fresh-keeping effect for cherry tomatoes was better than that of PE fresh-keeping film, and the preservation period was prolonged 6 days compared with the blank group.