The ship mooring force acting on the mooring dolphin of open crude oil terminal is one of the key design parameters of the structure. To counter the inconsistency of the selection principles adopted in different projects of the water transport industry, we propose to consider comprehensively factors including the calculated mooring force, strength design of the releasing hook, terminal safety conditions, and the impact on the structure,etc. We also illustrate the importance of a careful analysis and selection of the mooring force acting on the structure by analyzing the engineering case.