Abstract: Disclosed is a protective device of a lighting assembly, the lighting assembly comprising at least one LED, a first end lamp base and a second end lamp base, and the protective device including a first detecting module and a second detecting module and a driving module. The first detecting module and the second detecting are configured to detect a connection state of the first end lamp base to output a first detecting signal, and a connection state of the second end lamp base to output a second detecting signal. The driving module is connected to the at least one LED and configured to control the at least one LED to work based on the first detecting signal and the second detecting signal. The present disclosure also discloses a lighting assembly including the protective device and a protective method of the lighting assembly.