The invention discloses a machining process of a thin-wall gear ring. The machining process comprises the steps: 1, material selecting is conducted, and specifically, a hollow steel pipe is selected as a machined raw material; 2, cutting forming is conducted, specifically, the selected hollow steel pipe is placed onto an automatic feeding system of cutting equipment, a thin-wall wafer is machinedaccording to a drawing, and the allowance is reserved; 3, rough turning is conducted, and specifically, the outer circle, a hole and the end face are primarily formed; 4, a workpiece obtained in the step 3 is polished; 5, heat treatment is conducted; 6, the quenched thin-wall wafer is taken out from a heating furnace to be cooled in air; 7, carburization is conducted; 8, pressure quenching is conducted; 9, impeller blasting treatment is conducted; and 10, nitridation treatment is conducted, specifically, heat preservation is conducted for 2-3 h, and then cold treatment is conducted through water. The machined gear ring is high in strength, good in abrasive resistance and high in surface hardness, comprehensive properties of the gear ring are effectively improved, the gear ring is directlymachined through the hollow steel pipe, thus forging is not needed, the deformation can be reduced, steel consumption is lowered advantageously, the manufacturing cost is lowered, and the utilizationrate of the material is increased.