Abstract: In order to achieve the irradiation ability for 8 inch mono-crystalline silicon, also to improve the irradiation quality, this paper studies and improves the irradiation technology for mono-crystalline Silicon in Min Jiang Test Reactor (MJTR). Neutron screen is set inside the irradiation tube to reduce the irradiation uniformity, and the layout of the reflector is increased to achieve higher thermal neutron flux, in order to meet the requirement of 8inch mono-crystalline silicon irradiation. Meanwhile, this paper optimizes the irradiation process, and designs and improves the semi-automatic control process. After the improvement of irradiation technology, the operation time is shortened by about half, the number of irradiation tanks can be increased by 2%, and the efficiency of irradiation production is improved significantly.