A parking space sharing system and method, relating to the technical field of parking space sharing. The system comprises a parking space information subsystem (10) and an information promotion subsystem (20). The parking space information subsystem (10) comprises a parking space sharing module (101) and a parking space usage module (102). The parking space sharing module (101) is configured to receive parking space sharing information sent by a user terminal, and to save the parking space sharing information to a parking space sharing database. The parking space usage module (102) is configured to receive shared parking space usage information sent by the user terminal, and to send the parking space sharing information of a shared parking space to the user terminal. The information promotion subsystem (20) comprises an advertisement publishing module (201) and an advertisement display module (202), and is configured to perform information promotion of the parking space sharing system. The parking space sharing system and method allow more users to know the shared resources of shared parking spaces, so that the shared parking spaces can be fully utilized. Therefore, the utilization rate of parking spaces is improved; the disadvantage of manual charging is overcome; and a great convenience is provided for users to park.