Photoacoustic signals were induced on slices of black powder and its components， which was radiated by 1064 nm laser pulses with 10 ns duration. The laser pulse energies were adjusted by regulating the number of fused silica plates on the laser path as attenuators. An optical fiber-based Michelson interferometer was utilized to detect the generated acoustic signals. Acoustic wave energy was estimated. A primary model was proposed to estimate the reaction rate of black powder. Detected phase changes were similar to each other， but the dimensions varied with laser pulse energy. Thermal reaction of blackpowder was not significant under laser radiation， but other reaction mechanism existed and enhanced the photoacoustic signal. Relationship between laser pulse energy and integration of absolute value of phase change is approximately linear. Reaction rate of black powder is positively related to laser energy， except for high-energy pulse. The maximum of reaction rate was about 20 mmol·s^-1， which was achieved when laser energy is around 10 mJ.