Bicycle renting and returning system

The invention discloses a bicycle renting and returning system. The bicycle renting and returning system is characterized in that when an APP starting key is pressed, a bicycle APP controller activates a second bluetooth communication module on a mobile phone controller and activates an SIM communication module to wirelessly connect with a server; the mobile phone controller receives first bluetooth communication module connection passwords sent from the server, and enables the first bluetooth communication module to be in accordant connection with the second bluetooth communication module, and activates a power key of an electronic lock to enable the power key to be displayed on a display module on the bicycle APP controller; when the power key of the electronic lock is triggered, the bicycle controller unlocks the electronic lock; and a charging module on the bicycle APP controller starts charging until the power key of the electronic lock is triggered again. Therefore, the bicycle renting and returning sys