Abstract: LNG unloading arm is a critical equipment in LNG terminal, and its installation is a key part of engineering construction of LNG terminal, which directly relates to the entire engineering construction progress. This paper briefly introduces the structure and composition of LNG unloading arm made by SVT (Germany), and expounds the assembly process and techniques of LNG unloading arm in different phases. Besides, this paper comprehensively sums up the key technologies in the assembly process of the unloading arm, including lifting and transportation technologies of all parts of the unloading arm, warehouse and work barge dock packaging techniques prior to the installation of unloading arm, connection technique of inner tube of unloading arm, installation technique of 3D rotating components, positioning and installation techniques of counterweight of unloading arm, nitrogen blanketing and lightning grounding techniques of unloading arm, and indicates the considerations in the assembly process of unloading arm. All these can provide references for the installation of LNG unloading arms in LNG terminals in the future.