Nanjing metro line 3 pp stand to crow temple station double shield interval delay meters 2677.864 meters, the design USES two German harry recovered jewels earth pressure balance shield construction type. Shield method is the most useful range at enron, construction technology, but the shield cutter replacement, is a big hard in the process of shield tunneling. Belt cutter replacement need sponsorship compressed air pressure equipment, warehouse add pressure on soil, water in the soil bin replacement by air, soil, with some air pressure on the water and soil pressure, air pressure inside and outside warehouse set up soil storehouse of water and soil pressure balance, and then by professional staff into the soil bin with homework, for cutting tool replacement, work difficulty is high, the risk is big. Projects department professional craft staff force row all the difficult, in conjunction with the sponsorship of compressed air equipment, smoothly completed the shield construction machine blade replacement, swallowed another major projects of hard, encourage all project staff morale, also in shield construction crafts for the company growth on the control of valuable experience.