The quantitative analysis of explosives is very important for national defence and security inspection.However, conventional analytical methods are complicated and time-consuming because of the complexity of the explosive samples. Herein, we proposed a new quantitative method, which combined ultraviolet (UV) spectrophotometry with partial least squares regression (PLS-1 and PLS-2), to quickly determine the content of 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclo-octane (HMX), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and 2,4,6-trinitrotoluene (TNT) simultaneously from mixed explosive samples. The calibration models were constructed by using 49 reference samples in the calibration set and optimized by full cross-validation. The predictive performance of the optimized models was validated by 21 explosive samples in an independent test set. The standard errors of prediction (SEP) were lower than 1.4 mg mL À1 for HMX, 2.2 mg mL À1 for RDX, and 0.8 mg mL À1 for TNT in both PLS models. Finally, the optimized PLS-1 and PLS-2 models were successfully applied to simultaneously determine the three explosive ingredients in eight polymer bonded explosives (PBXs). The average recovery was close to 100% for each of the three components. Thus, UV spectrophotometry combined with PLS regression can be considered as a promising strategy to conduct the determination of HMX, RDX and TNT in practice.