The invention provides an optical system and a laser radar, belonging to the field of laser radar measurement. The laser radar comprises a laser emitting device, a reflecting device, a wedge lens, an object lens component, an eye lens component, and a detecting device. After being reflected by the reflecting device, laser emitted by the laser emitting device is incident on the wedge lens and refracted and deflected. When the wedge lens is rotating, the emergent laser circularly scans a target with the rotation of the wedge lens. The laser reflected by the target and transmitted through the wedge lens is incident on the detecting device through the object lens component and the eye lens component in sequence. When the optical system provided by the invention is applied to the laser radar, back-end computation of the laser radar can be simplified.