Abstract: The design and related technical measures of the resonator for the first nuclear reactor pumping ³He-Ar-Xe laser in China are given.As we know that the reactor pumping laser belongs to the area of large scale physics experiments. Atpresent we also lack of some measured parameters for the design of the resonator, so that all of the respects of the resonator are studied and the related technical measures are taken to ensure the oscillation of the laser.