Calorific value is a major indicator of the quality of coal. In this study, we use nanosecond, femtosecond, and dual-pulse laser-induced breakdown spectroscopy (LIBS) to quantitatively analyze the calorific values of 18 standard coal samples exhibiting different calorific values. The comparison of nanosecond and femtosecond plasma spectra denotes that the femtosecond plasma spectra exhibit less continuous noise and better signal-to-noise ratio when compared with those exhibited by the nanosecond plasma spectra; further, the relative standard deviation of the spectral line intensity is smaller, whereas the stability is higher. Femtosecond laser-induced breakdown spectroscopy (fs-LIBS) can obtain high linear fitness of the element content without any baseline correction but it has the disadvantage of weak spectral intensity. We construct a dual-pulse LIBS system using a femtosecond laser as the spectral excitation source and a nanosecond laser for plasma heating. Experiments denote that the dual-pulse LIBS can considerably enhance the emission lines. Finally, we combine nanosecond, femtosecond, and dual-pulse LIBS with the partial least squares (PLS) method to quantitatively determine the calorific values of coal samples. The fitting degrees of the calibration curves (R²) are 0.9553, 0.9897, and 0.9964 for the three aforementioned methods, respectively. The use of dual-pulse LIBS can effectively improve the accuracy of the quantitative analysis of the calorific value of coal.