Wear failure of oil drill bits leads to cost increase, and how to improve the abrasion resistance of cemented carbide (WC-Co) drill bits is an urgent problem, and deep cryogenic treatment (DCT) is a feasible method. The effect of DCT time (i.e., 0, 3, 6, 9, 12, 24, and 48 hours) on the Vickers hardness, flexural strength, and wear rate of WC-Co with different Co contents (i.e., 5 wt%, 8 wt%, 10 wt%, and 12 wt%) was investigated. The results showed that the best DCT time for hardness, flexure strength, and abrasion resistance of WC-Co was 12 hours. Compared with untreated (e.g., 0 h), the wear rates of WC-Co with different Co contents were reduced by 36%, 34%, 30%, and 19%, respectively at DCT-12. Compared with WC-12Co, the wear rate of WC-5Co with different DCT times was reduced by 75%, 77%, 78%, 78%, 80%, 79%, and 78%, respectively. The precipitation of η phase (Co6W6C), martensite phase transformation (α-Co to ε-Co), and the increase of residual compressive stress (RCS) of WC after DCT improved the hardness, flexural strength and reduced the wear rate of WC-Co. Based on the principle of frictional wear, a micro-cutting wear model considering Co content and DCT time is proposed, which can predict the evolution of the wear rate of WC-Co. The results of the study guide improving the wear resistance of drill materials.