The invention provides a testing method for the tensile strength of an ultra-thin Ti / Al two-layer gradient material. The testing method comprises the following steps of: step 1, designing an original sample, preparing the original sample, recording the thickness and preparation process of each layer of the original sample at the same time, and proportionally amplifying the thickness of each layer of the original sample to obtain a series of amplified samples under the same preparation condition as the original sample; and step 2, testing the tensile strength of the series of amplified samples, fitting testing results to obtain a fitting equation, and calculating the tensile strength of the original sample according to the thickness of the original sample after the fitting equation is obtained. According to the testing method for the tensile strength of the ultra-thin Ti / Al two-layer gradient material, welding conditions and the difficulty of testing an ultra-thin sample are comprehensively considered, and the scientific detection of the mechanical properties of the ultra-thin material is realized for the first time by optimizing the conditions of the amplified samples.