Abstract: Ultra-high molecular weight polyethylene (UHMW-PE) fiber fabric reinforced-polyethylene (PE) coat flexible composites were taken as research object. Firstly, the cross-section of the composites was polished by ion polishing instrument, and then the microscopic structure of the composites was measured through SEM and optical microscope. In this way, the microscopic geometry parameters of the composites were got. Finally, based on homogenization method and continuum hypothesis, mechanical model of unit cell was set up, and tensile load-strain curve of unit-cell was calculated. The theoretical values were compared with the experimental values. The results show that the tensile load-strain curve obtained by mechanical model of unit-cell of the composites based on multi-dimension method was in good agreement with the tension load-strain curve obtained by experiment. The theoretical model is better able to predict tensile modulus of fiber fabric reinforced flexible composite.