The present invention relates to a beam field based patient alignment method and system using a light field and a body surface adhering light reflector. An object alignment system using a light reflector, according to one aspect of the present invention, can comprise: a user input unit for presetting a first region in which radiation is to be emitted at an object； a display unit for displaying information on the first region； a radiation emission unit for emitting radiation at the first region when a light reflector formed to correspond to the shape of the first region is attached into the first region； a light emitting unit for emitting light, at the first region, in the same direction of the the radiation； a camera for photographing an emission region of the light reflector when the light reflector emits light by using the light； and a control unit for controlling the display unit such that the display unit additionally displays the emission region of the light reflector, having been photographed by the camera, and determining whether the radiation is being emitted at the first region according to whether the region of the light reflector is included in the first region.
