A method using bovine β-lactoglobulin as the adulteration marker was developed for the qualitative and quantitative detection of cow milk in adulterated camel milk by ultra-high performance liquid chromatography (UPLC). The effects of different heat treatments on the adulteration marker were discussed to meet the need for the detection of different commercial camel dairy products. The results showed that this method could effectively detect milk in adulterated raw camel milk, pasteurized camel milk and camel milk powder. The regression equations of the three adulterated milk samples showed good linearity, with correlation coefficients (R²) of 0.9979, 0.9969 and 0.9978, respectively. The limits of detection for the adulterated samples were 2%, 3% and 5%, respectively, which could meet the detection requirements. Using this method, out of 10 different brands of commercial pure camel milk powder, four were found to be adulterated.