As the oil and gas industry is moving into drilling and production operations in much deeper waters and harsher environments,there is a great demand to de-velop the next generation tools and technology to meet these challenges.The environments in which subsea system working on must operate are necessarily harsh.So the development of such system involves careful consideration of the environmental and operational require-ments.Nonlinear Finite Element Analysis (FEA) model for such system is established in a realistic way,it not only allows designs to be undertaken for complex scenarios that were not previously possible,but also gives the designer to have more opportunities to design the subsea system both safe and cost effective.This paper presents three latest subsea system de-signs based on FEA.The first part focus on the improvement of seal structure design,which takes into account the proper relationships between the size and shape of the metal sealing units to achieve effective seal based on ABAQUS,thereby reducing the possibility of seal failure caused by improper distribution of structural stress.The second part is the design of a new pull-up metal-to-metal seal suitable for subsea wellheads,this design involves special structure differed from earlier types.Its actuated by pull-up force which obtained from the drill pipe.The last one demonstrates how FEA can be used to verify the reliability of connec-tion system of subsea running tool,as it ensures that the load transfer and interactions be-tween the running tool and wellhead are properly accounted for during installation.The above analysis tool allows solving some of the most complex engineering problems,and in some cases has allowed significant cost savings to be achieved in the engineering field.