Furosine, an indicator to assess the heat load on milk and dairy products, is closely related to the early stage of Maillard reaction. It is formed from Amadori products, with a reproducible yield after a same acid hydrolysis procedure. However, the acid hydrolysis in the standard detection method, which requires 16 to 23 h at 110°C in oven, is time-consuming. This study investigates an UPLC method using microwave digestion for furosine detection. Liquid milk was added into the high-pressure tube with hydrochloric acid and microwave digested at 160°C for 1 h, followed by filtration, dilution, UPLC separation and PDA detection at 280 nm. The results showed that the new method was time-saving, with a reproducible yield which was also investigated using the same pasteurized and UHT milk samples (n = 24). Compared with the standard method, microwave digestion showed 15–20% decrease on furosine quantitation for both pasteurized and UHT milks. Thus, a correction factor was used to normalize the results when comparing to the standard method. Moreover, method validation was taken, with the results as followed. The LOD and LOQ were 3 µg/L and 10 µg/L, respectively; the linearity range, calibrated by diluted furosine standards in matrix solvent, were 0.2–5.0 mg/L, with determination coefficient R² > 0.9999; the recoveries of various concentration of furosine in liquid milk were 84 to 106%, with RSDs ranged 0.2%~7.1%. Therefore, this UPLC method using microwave digestion is timesaving and revolutionary in the quantitation of furosine.