Abstract: A bar signal light structure mainly includes a base body and a bar connected to the base body. Inside the base body is disposed a lamp holder which may slide along the base body. On the lamp holder is disposed a control circuit. To one side of the control circuit is electrically connected a light-emitting component. To another side of the control circuit is electrically connected a button holding against the back edge of the base body and a USB plug protruding from the back edge of the base body. The bar caps a handle of a bicycle. Before turning left or right while riding a bicycle, a user may press the lamp holder to press the button, which activates the control circuit to cause the light-emitting component to flash as a warning to enhance road safety. When not in use, the base body may be disassembled from the bar and plugged to a computer or a battery charger for recharging.