The construction scale of the urban Metro works in China is becoming larger and larger. However, the construction cost of the urban Metro works is becoming lower and lower. Making rational technical optimization on Metro works based on lump sum contract has become one of the most important means for construction enterprises to make more profits. On basis of works cases, the author analyses the technical optimization means of the cutandcover Metro works and mining Metro works based on lump sum contract. The technical optimization has achieved good economic efficiency. The author concludes that appropriate technical optimizations can not only achieve better economic profit, but also can achieve better construction efficiency.