Abstract: With 45 steel as an example, the data processing steps in fatigue test were introduced, including sample data sorting, scatter plot chart drawing, fatigue equation and curve building with regression analysis, the calculation of relative error and residual standard deviation, and reliability-fatigue stress-life equations and curves establishing. The highlight of the discussion is to use matching method for stress of censored life; and establish the fatigue equation with decimal power, with the relative error instead of significant inspection.