Due to the integrity，differential settlement，engineering cost，and other reasons，the breast wall structure in large sheet pile wharfs requires a long segment，whose length often breaks through the upper limit as stipulated in standards. In view of the extra-long breast wall structure used in the Nansha Phase IV wharf project of Guangzhou Port，this paper establishes a three-dimensional finite element calculation model of the breast wall and considers the influence of concrete shrinkage and environmental temperature change during the calculation. The calculation results show that the structural internal force of the breast wall with a 100 m segment is much stronger than that of the common wall，and the displacement and internal force of the breast wall show different changing trends. The breast wall structure with a 100 m segment has achieved positive results in the Nansha Phase IV wharf project of Guangzhou Port.