The invention provides a White cell adjusting device and method. The adjusting device comprises a two-dimensional adjusting frame, a motor, an area-array detector, a storage and a computing module; the motor is arranged on the two-dimensional adjusting frame, and at least one of two reflectors which each has a smaller radius of curvature and is opposite to a reflector with a larger radius of curvature in a White cell is adjusted in a two-dimensional mode according to the adjustment amount transmitted by the computing module; the area-array detector is arranged on an emitted light path of the White cell, and the positions of an emitted light spot on the area-array detector are obtained; the storage stores a mapping relation between the adjustment amount of the motor and the migration distances of the light spot on the area-array detector; the computing module obtains deviations according to the positions and a set position and obtains the motor adjustment amount corresponding to the deviations according to the mapping relation, and the adjustment amount is transmitted to the motor. The White cell adjusting device and method has the advantages of being high in precision, simple in structure, low in cost and the like.