Abstract: Based on the practical application of injection production integrated string technology in Bohai oil field and related literature,the performance analysis of the special shaped blade spring in the automatic steering tool was carried out. The high temperature compression and the one year high temperature and atmospheric pressure test of the special shaped blade spring were completed,and the changes of its mechanical properties under high temperature conditions were obtained. Based on the test results,it can be seen that the blade spring will reach a stable state after working at 250 ℃ for about half a year,and its maximum elasticity will be reduced by about 10 %~30 %. Meanwhile,the material parameters of the blade spring were modified. Based on the modified material parameters,a total of 35 sets of comprehensive dimensional simulation analysis were carried out on the thickness and width of the blade spring. The relationship curves between the thickness and width of the spring on the maximum elastic force and the maximum plastic deformation were obtained,and the mathematical model was established,which can provide reference for the practical application of the steering tool.

Key words: special shaped spring, experimental analysis, numerical simulation, constitutive model