Disclosed are a spike light and an outdoor lighting system. The outdoor lighting system comprises a power module, a relay module, spike lights and a PIR detection module, wherein the relay module receives a signal sent by the PIR detection module and transmits the signal to the power module; the power module receives and process the signal transmitted by the relay module, and meanwhile controls the on/off of the spike lights; the spike lights comprise a number of spike lights, each of which includes lighting lamp devices and a post, the lighting lamp devices being mounted on the post, electric wires being provided within the post; and, each of the lighting lamp devices comprises a lamp and a socket assembly, a pin electrically connected to the lighting lamp device being provided on the socket assembly, the pin being inserted into the post and puncturing the electric wires within the post.