In this paper, we propose a composite optical system for automotive headlamps. The system is composed of a paraboloid collimating reflector, an off-axis paraboloid reflector, a baffle and an imaging len. By using a LED as the light source, precise light distribution can be achieved. When making ray-tracing simulation for the composite optical system in TracePro, a clear cut-off line can be seen on the measuring screen, as well as a hotspot at the centre. The power consumption for the LED light sources in this system is less than 10 W, resulting in an energy efficiency of more than 58% and a maximum illumination of 26.76 lux at the centre hotspot.