The invention discloses a flexible-packaged lithium ion battery. The flexible-packaged lithium ion battery comprises a shell and a bare battery core arranged in the shell, at least one through hole isformed in the top sealing edge or the side sealing edge or the bottom sealing edge of the shell, and is formed in the end of the shell, and a liquid injection tube is embedded into the through hole.According to the flexible-packaged lithium ion battery, the through hole is formed in the top sealing edge or the side sealing edge or the bottom sealing edge of the shell, the liquid injection tube is embedded into the through hole, and after the battery is circulated to reach a certain number of times, the liquid injection tube can be cut open with laser or a cutter to conduct secondary liquid injection, and is sealed through sealing gum finally; the service life of the battery can be effectively prolonged, the using rate of resources is increased, and the recycling pressure of battery industries can also be greatly released. A preparing method is simple, great economic benefits can be generated, popularization and application are facilitated, and the flexible-packaged lithium ion battery is applied to the technical field of batteries.