Abstract: Aiming at the problem that the sample of thermal simulation compression test was small and the tensile test could not be carried out directly, the tensile test of small sample was carried out by using the self-made small sample fixture. Through small sample tensile test and hardness test on 8 kinds of samples with different strength levels, the correlation between them was analyzed. The analysis results of small specimens and standard tensile specimens were compared. The results show that the tensile test results of small specimens and standard tensile specimens were basically the same, and the standard deviation of tensile strength was less than 3. 00. The tensile strength of materials could be accurately determined by small specimens.