Excavation method of shield launching shaft rear pilot tunnel

An excavation method for a shield launching shaft rear pilot tunnel comprises the following steps that a, after shield launching tunneling, inclined struts of a reaction frame for shield tunneling are dismantled, and the reaction frame serves as a back wall to provide reverse thrust for pipe jacking construction; b, rear pilot tunnel pipe jacking construction is conducted; c, earth excavation is conducted; and d, after the pipe jacking construction reaches the designed distance, end wall construction is conducted. The shield launching reaction frame is used as a back wall, a rear pilot tunnel can be conveniently excavated in a launching well, a storage battery car track can be prolonged, storage battery car sets can be fully arranged to be put into use, the number of times and time of reciprocating of storage battery cars are reduced, and the shield tunneling construction progress and efficiency are guaranteed, and the method belongs to the technical field of tunnel construction. 一种盾构始发井后导洞的开挖方法，包括如下步骤：步骤a：盾构