Abstract: The optical collimating and laser locating system is the supplementary instrument of the cancer-curer. The collimating part is used to imitate the axis of of neutron beam and irradiating field of neutron, the laser locating one is used to display the place of two parcentral points in the space of curing room. The system consists of five He-Ne lasers and other complementary parts. The beam slitter of neutron-visible light is made of thin Aluminum, with reflectance no less than seventy per cent. The warning signal arises when the shift of beam is greater than 0.3m rad.