A liquid cooling method for cooling LED lights used for minimally invasive surgeries is provided. The LED lights are integrated with the micro camera so that only one pipeline is needed to accommodate the electrical wires and cooling liquid conduits. The electrical wires disposed in the electrical wire conduit provide the path for electrical power required by the micro camera and the LED lights as well as the electronic signals from the micro camera. The liquid conduits guide the circulating cooling liquid to pass by the bottom surface of the LED substrate and carry the generated heat off the human body.