The field experiment is carried out on the connection gallery of Wuxi Metro Line 3 constructed by pipe jacking method so as to study the response of the main tunnel during the construction of the pipe jacking method of T-connected tunnel. The construction process is understood by studying the nodes of construction conditions in the construction process, and the settlement of the main tunnel, the structural convergence and the strain of the structure are measured and studied. By studying the detailed construction steps, working stages, settlement and tunnel convergence rules, the conclusions, i.e. the whole construction process is relatively safe, and the main factors affecting the structural response in the construction process are the variations of shield thrust and internal support force, are drawn. Through the experimental study, the feasibility of T-connected tunnel by pipe jacking method is analyzed and the key influencing factors are given.