Abstract: Taking the super-shallow buried mined tunnel with large span at the Xibocheng station of Chengdu met? ro line 18 as an example, aiming at the deficiencies of original design of CRD method, a technical scheme for settlement control and optimization of CRD construction of the super-shallow buried large-span mined tunnel underneath an existing tunnel is proposed, the auxiliary measures of jet grouting pile, advance large pipe-roof and condulet grouting are adopted to reinforce stratum, and the small-section bench method of CRD and partitioning lining construction schemes are optimized. The practice shows that the optimized CRD construction method and measures are effective, decreasing the safety risks and speeding up the construction speed and reducing construction cost.