1. An optical imaging system using multiple light sources, comprising: a first light source generating a first light modulated with a first frequency; a second light source generating a second light modulated with a second frequency; a camera simultaneously detecting multiple lights output from an object after the first and second lights are illuminated on the object and outputting multiple image detecting signals; and an image processing unit processing the multiple image detecting signals to obtain a first image representing a shape of the object and a second image representing a desired target portion of the object.