36MnVS4 is a new generation of non-quenched-tempered（NQT） steel for medium-carbon micro-alloying connecting rods. Through V micro-alloying and nitrogen-controlled design， this steel achieve excellent comprehensive mechanical properties for the connecting rod.， So it is widely used in the manufacturing of passenger car engine connecting rods. However， in the production process of NQT connecting rods， there are often typical connecting rod defects such as uneven fracture or slag dropping，which seriously affects the assembly quality and performance of the connecting rod after fracture. Especially in the production process of 36MnVS4 connecting rods， this problem is more prominent. To this end， a systematic inspection， analysis and research on the fracture split defects of the 36MnVS4 connecting rod were carried out and the controlled forging and cooling process optimization was proposed. The optimal controlled forging and cooling process for the 36MnVS4 connecting rod has been established. The process parameters are implemented： rapid cooling above 660 ℃ to inhibit the precipitation of ferrite， and slow cooling below 660 ℃ to obtain coarse lamellar pearlite， ensuring that the connecting rod has qualified hardness indicators and has good expansion and breaking performance.