Abstract: Compared with other advanced pre-support technologies, the pipe curtain support has high stability and good safety, and is widely used in soft soil layers. In this paper, in view of the complex surrounding environment of urban tunnels, the comparative analysis is performed for small-pipe curtain construction methods in strongly and moderately weathered mudstone stratum, the horizontal spiral guided drilling, reaming and pipe jacking method is proposed accordingly and relevant key technologies are studied as well. Then, the telescopic drill bit is studied and applied, and the construction measures for pipe curtain jacking accuracy control, trajectory control and jacking resistance reduction are put forward on the premise that the construction method is feasible. According to the design of the engineering support system, the alternative measures of arch foot-locking anchor pipes are proposed to ensure construction quality and safety.