Abstract: Active fault is a major geological hazard threat to submarine pipelines, which may subject to excessive axial deformation and fail from the faulting. Thus an improved analytical method for strain of submarine pipeline under strike-slip faulting was proposed in this paper. The nonlinear constitutive relation of pipeline materials was considered based on the linear strengthening model, and the influence of soil nonlinear constraint on the response of the pipe structure was accurately calculated through the nonlinear soil spring model with ideal elastic-plastic constitutive relation. From the differential control equation of the pipeline stress, analytical results of the axial strain in the pipeline were derived and the expression of the pipe elongation was obtained. Based on the equilibrium equation and iterative calculation, the stress and strain of the pipeline can finally be accurately calculated. Compared with the finite element calculation results, the improved analytical method for pipe strain has higher calculation accuracy than the existing recommended method (i.e. Newmark method).