The work aims to explore a technique which can significantly improve wear resistance of 65Mn spring steel to meet the performance requirements in high wear environment. 65Mn was treated with QPQ by virtue of orthogonal test to explore the effects of nitriding temperature, nitriding time, oxidation temperature and oxidation duration on the microstructure and wear resistance of the samples by means of metallographic observation, SEM scanning and energy spectrum analysis as well as abrasive wear. And the conventional QPQ and thorough QPQ treatment schemes were optimized. The results of QPQ analysis showed that samples treated with QPQ were composed of oxide layer, loose layer, compound layer and diffusion layer from the outside towards the inside. In the samples treated with thorough QPQ, there was a layer of nitrogenous austenitic layer between the compound layer and diffusion layer. Main phase of the oxide layer was Fe3O4 while that of the compound layer was Fe3N. The distribution of C, N and O elements in the sample treated with QPQ after line-by-line scanning exhibited some regularity, i.e., the C elements were mainly on the surface, the N elements were mainly in the dense compound layer while the O elements were mainly on the surface and in loose holes. In the thorough QPQ process, the oxide layer is 15 μm thick, the compound layer 30 μm and the austenite layer 10μm when co-cementation continues for 2 hours at 640 ℃ and oxidation process 40 minutes at 350 ℃. After thorough QPQ treatment, the wear rate of 65Mn is up to 65Mn and is provided with excellent wear resistance while the wear rate is 0.166 mg/m.