The influence of blasting vibration on the adjacent buildings is inevitable if blasting is employed for excavation. Daping station tunnel of Chongqing light railway project, on which there is dense with population and buildings, has a minimum buried depth of only four meters and maximum span length of 26.3 meters. The stepped excavation mode with shorthole, multiround and Vshaped cut are adopted. The maximum charge weight of one delayed interval is determined by the permitted vibration velocity. The smooth blasting technology with adding vibrationreduction holes is used. Meanwhile, the charge weight per hole is strictly controlled. With the simulation and onsite test, it is found that the proposed technology for tunnel construction is feasible.