The concentration of furosine in liquid milk, as an indicator to assess the heat load on dairy products, can be used to distinguish different processed milk. The most established detection methods, based on the international standard (ISO 18329:2004/IDF 193:2004), includes acid hydrolysis of milk, solid-phase extraction, HPLC separation and PDA detection at 280 nm. However, the pretreatment is tedious and time-consuming. In this work, we developed a simple and time-saving UPLC method for furosine detection. Water film is used, instead of solid-phase extraction, which lead to easier operation, time and cost savings, and 10% recovery increased. The total runtime, instead of 32 min in the international standard method, is only 8 min. The limits of detection and quantification are 3 and 10 µg/L, respectively. The linearity range, calibrated by diluted furosine standards in matrix solvent, are 0.2 to 5.0 mg/L, with determination coefficient R² >0.9999. The recoveries of various concentration of furosine in different liquid milk samples ranged from 78.4 to 112.6%, with relative standard deviations of 0.1 to 6.7%. Moreover, 34 liquid milk samples were measured for their furosine concentrations. The results (furosine content of 4.0–6.8, 9.1–14.2, and 148.3–197.6 mg/100gprotein for raw milk, pasteurized milk, and UHT milk samples, respectively) indicated the furosine amounts increased with increasing heat load applied. Therefore, this simple and quick UPLC method can be used to test furosine concentration in liquid milk.