An oil-immersion quenching cooling precursor and an oil-immersion quenching cooling method includes an axle-type workpiece or a workpiece that has sections in an axle form. Several separation rings are arranged on the workpiece in the axial direction to separate the axle-type workpiece or the workpiece that has sections in an axle form into a plurality of sections before oil-immersion quenching cooling. In the method, there is a cutting procedure before a quenching cooling procedure. Several separation rings distributed in the axial direction are reserved outside a dimension required for the workpiece. sections before oil-immersion quenching cooling. In the method, there is a cutting procedure before a quenching cooling procedure. Several separation rings distributed in the axial direction are reserved outside a dimension required for the workpiece.