In order to study the influence of Carbon nanotubes on the mechanical properties for multi-layer materials material,in this paper,the mathematical model between the content of carbon nanotubes and mechanical properties of multi-layer material was proposed to predict the mechanical performance of multi-layer material.First,introduced the functional relationship between reinforcing material content and the Young ’s modulus of composites materials,and then deduced the relationship between reinforcing material content and the Young’s modulus of multi-layer materials based on multi-layer beam theory transform section method.Finally,we can get the basic parameters of the mathematical model on carbon nanotube multi-layer material by bending experiments to reveal the impact of carbon nanotubes on the mechanical properties of multi-layer material.This method of establishing a mathematical model is also applicable to other reinforcing material and the application of new multi-layer material has a positive significance.