The quality defects of railway tunnels have serious impact on the construction and operation of the tunnels. However, quality defects such as water leakage, lining cavity and lining crack often occur to railway tunnels. In the paper, the measures taken to prevent quality defects during the construction of Yangjiawan tunnel, including the design and manufacturing of the lining formwork trolley, the arrangement of steps at the lining ends, the installing of the longitudinal waterstop ties by traction means or by suspension means, the laying of the waterproof sheets and the concrete casting layer by layer are presented. In the end, the quality defects of lining cavity and water leakage are eliminated.