Abstract: In the construction of twin-line parallel shield tunnel, many factors are causing surface settlement, such as the distance between two tunnels, tunnel depth, tunnel diameter, geological condition, construction procedure and level. On the basis of ground settlement monitoring data of twin-line shield excavation of typical geological units in Zhengzhou and Peck formula, ground settlement distribution function relationship is established. Through fitting analysis of field data, values of parameters including width of settlement trough and soil loss rate are obtained. Study founds that, under the condition of fixed distance between tunnels, ground settlement curve demonstrates W shape when the tunnel depth is relatively shallow, which can be fitted by using the revised 2D Peck formula; when the tunnel is relatively deeper, ground settlement curve demonstrates V shape, which can be fitted by using classic Peck formula to meet the engineering accuracy requirement.