A packaging bag comprises a bag body and a mould-proof preservation coating layer, wherein a storage cavity is formed in the bag body, and the mould-proof preservation coating layer is arranged on the inner surface of the storage cavity; the raw material of the mould-proof preservation coating layer is a mould-proof preservation coating which is prepared from components in percentage by weight as follows: 20%-60% of resin, 30%-70% of a solvent, 0.5%-10% of a mould inhibitor and 0.3%-5% of an auxiliary, wherein the resin is at least one of polyurethane, a acrylate copolymer, polyvinyl alcohol, polyvinylidene chloride, modified polyvinylidene chloride, an ethylene-vinyl acetate copolymer, a polyvinyl acetate copolymer and a vinyl acetate-butyl ester copolymer, and the solvent is at least one of water and ethyl alcohol. According to the packaging bag, the surface of the mould-proof preservation coating layer on the inner surface of the storage cavity is dense and pore-free, and the mould-proof preservation coating layer has better effects of keeping constant moisture and preventing mould by aid of addition of the mould inhibitor. The packaging bag is particularly suitable for preserving food such as fruit, bread, tobacco and the like which have shorter storage life, are prone to mould within short time and need to be eaten timely.