58SiMn steel can be used as a kind of material for projectile-like barrel parts. During producing barrel parts, the microstructure of the barrel parts will be changed due to its hot deformation at certain high temperature, which resulted in the variety of the part’s mechanical properties. It is necessary to optimize the parameters for recrystallization process by prediction and simulation. The double-pass hot compression tests were conducted using Gleeble 1500 System at different deformation temperature, strain rate and pre-strain. Effect of pre-strain, deformation temperature on the curve of stress-strain has been analyzed. The static recrystallization fraction of double-pass hot deformation was computed and analyzed using compensation test. The actual grain size was measured by metallographic method using oxidation process, which overcomes the difficulty in revealing grain size of 58SiMn steel. The oxidation process was the method of heating the martensite in very fast speed and use of its microstructure inherent characteristic and regarding the size of austenite grain as the maximum of martensite plate. Using regression of the experimental data, the mathematical model of static recrystallization is set up. The average grain size of 58SiMn steel during hot deformation was calculated by deform-3D software and verified by experiment. The results show that the rate of static recrystallization was in direct proportional to the pre-strain of the steel. The grain size decreased with the increase of holding time at low deformation temperature 1173 K and pre-strain 0.10. The mathematical model proposed could be used for predicting the static recrystallization behaviors of 58SiMn steel.