The invention discloses a design method of a steel casting thermal treatment process based on multiple regression analysis. The method comprises main steps as follows: a prediction model between the heating speed for thermal treatment of steel castings and impact factors impacting the heating speed is established, a large quantity of experimental schemes are formulated, experimental data are subjected to regression analysis, and a heating speed calculation formula for thermal treatment of large steel castings is finally determined. The calculation formula is used for guiding selection of parameters of the thermal treatment process for the large steel castings, blindness of parameter selection of the thermal treatment process is avoided, the stability of the thermal treatment process of thelarge steel castings is guaranteed, and the quality stability of the castings is also improved.