To investigate conditions that are likely to produce a boiling-liquid-expanding-vapor explosion (BLEVE), the determination of homogeneous nucleation rates of superheated liquids is often crucial. A new approach to estimate nucleation rates of superheated liquids is proposed; the approach is based on the probability distribution of the energy fluctuation within the framework of statistical thermodynamic fluctuation theory. Formulae for calculating the homogeneous nucleation rate in Gibbs canonical ensembles are deduced and tested for some substances. The calculated rates are compared with those obtained by the commonly used kinetic method as well as with experimental values. Finally, the new approach is validated by analyzing pressure rebounds of rapid discharge of pressurized liquefied petroleum gas (LPG). From the pressure rebound conditions, estimates of homogeneous nucleation rates can be obtained with both the kinetic and energy fluctuation approaches. Comparison of calculated results reveals that the new energy fluctuation approach is reasonably effective and has practical relevance in BLEVE research.