Optical imaging system

This invention provides an optical image system for forming an image against an object in space including an image unit, a first light conduction unit and a second light conduction unit, among which, the image unit is defined to have a first side and a second side, a first optical path is defined from the object to the first side of the unit and a second path is defined from the second side to the image, said first light conducting unit is installed on the first path for leading the light to run along the first path from the object, said second unit is installed on the second optical path for leading the light running along the second path to be imaged in the space to reduce the volume of the optical image system.