An optical-fiber connector includes an insulative main body having a pair of optical components extending forwardly therefrom. Each optical component defines at least one lens and a guiding post located at outside of the lens. Each guiding post defines a through hole extend through the guiding post and the main body in a front-to-back direction and fulfilled with the air for transmitting a test light. The test light from the through hole of the guiding post acts as an accurate measuring reference of the true position between the lens and the fiber because of having no displacement of the light path through a through hole.