The lateral launching scheme of shield，using shaft and π shaped double-cross channel，is adopted for Changchun Metro Line 2 between Nanguan and Yanchang. The proposed method successfully overcomes the problem that the shield launching shaft cannot be set up directly on the truck road. CRD method is applied to the cross channel with six pilot tunnels. Relying on this project，the ground subsidence deformation characteristics during excavation of π shaped double-cross channel were analyzed using field measured data，theoretical analysis method and numerical simulation. The research shows that the patterns of ground deformation caused by right and left cross channel excavation are basically the same. The ground subsidence，which starts from the intersection between arc segment and line segment，is the largest and is always beyond 30 mm. The area of the section is about four times of the tunnel diameter. More than 85% of the total ground subsidence is caused by the excavation of the first four pilot tunnels(upper-left，mid-left，upper-right and bottom-left pilot tunnels) and the stratum loss rate increases proportionally along with the increase of excavation areas of the cross channel. With the proceeding of the last two pilot tunnels excavation(mid-right and bottom-right pilot tunnels)，the stratum loss rate gradually decreases. The research results can provide reference to the construction and can be adopted for similar engineering.