An accurate nonlinear hygrothermal-electro-elastic (HTEE) buckling analysis of piezoelectric fiber reinforced composite cylindrical shells subjected to the coupled loading effects of axial compression and hydrostatic pressure is established by considering non-uniform pre-buckling effect. Nonlinear governing equations are derived based on higher-order shear deformation theory and Novozhilov’s nonlinear shell theory. Accurate critical buckling
stresses and pressures, and explicit buckling modes for both axisymmetric and non-axisymmetric buckling are obtained by the Galerkin method. A comparison between the new prediction and existing results is presented and excellent agreement is reported. A comprehensive parametric study of geometric parameters, end conditions, distribution patterns and hygrothermal-electric multi-physical fields on the buckling behavior of HTEE composite cylindrical shell is also analyzed and discussed.