Abstract: Quenching soft spots and quenching soft tapes of output shafts emerged after quenching in a company, which seriously influenced the performance and reliability of the equipment. By analyzing the characteristics of the quenching soft spots and quenching soft tapes, it was found the output shafts emerged quenching soft spots and quenching soft tapes mainly because the quenching batch and furnace charging way had problems, which resulted in the shortage of quenching cooling rate. By taking low concentration brine as quenching medium and changing the quenching operation mode, problems of quenching soft spots and quenching soft tapes could be thoroughly solved.