It is the first time in China that smalldiameter concrete segments (with the outer diameter being 4.1 m, the inner diameter being 3.6 m and the width being 0.8 m) have been used for the 220 kV cable tunnel from Xiniu substation to Qilin substation in Guangzhou, which has a 118 mturningradius section. In the paper, the bending capacity of the segments and the influence of the handhole on the stiffness of the segments are tested, and the deflection and crack width of the structure are measured. The loading process is simulated by means of 3D model using ABAQUS finite element software. The crack width is calculated by using methods specified in Code for Design of Concrete Structures (GB 50010—2002 and GB 50010—2010) and the calculation result is compared to the measured results. The study results show that: Bending failure occurs to smalldiameter shield tunnel segments, and the ductility of the segment is good; The measured crack width agrees well with results calculated according to Code for Design of Concrete Structures (GB 50010—2010); The influence of the handhole on the stiffness of the segments can be ignored.