The structural design of connection interface between opencut metro station and ventilation duct is discussed and analyzed in terms of structural arrangement and antifloating. The authors recommend that: 1) The arrangement of deformation seams and the design of beamcolumn system at connection interface should be strengthened and optimized and rational parameters should be adopted so as to guarantee the safety of the structure. 2) The antifloating calculation and antifloating measures should be strengthened for main structure at connection interface with high groundwater level. The relevant design of reserved interface are discussed as well.