The invention belongs to the laser gyroscope technology, and relates to an integrated light combination device and a light combination method for a laser gyroscope. The integrated light combination device for the laser gyroscope comprises an integrated light combination prism (1), an optical mask plate (2) and a detector (3), wherein the optical mask plate is arranged on an output surface of the integrated light combination prism, the detector (3) is located on an output surface of the optical mask plate, the upper end surface of the integrated light combination prism (1) is provided with a tangential surface, and an intersection angle between the tangential surface and the lower end surface of the integrated light combination prism is phi which is about 30 degrees. The integrated light combination device is simple and compact in structure, convenient to process and install, easy to miniaturize, and especially applicable to a microminiature laser gyroscope with the cavity length less than 4cm. In addition, in light combination, the width of a moire fringe can meet the requirement of the detector by regulating the intersection angle between a mask fringe and an interference fringe, the requirements on the processing error of the angle phi of the light combination prism and the optical debugging error can be greatly reduced, and the practicability requirement of the microminiature laser gyroscope can be met.