Simulation of interaction of laser pulse with gas particle mixtures plays an important role in environmental and engineering applications. The injection of metal particles with low evaporation temperature and ionization potential causes optical breakdown on individual particle, and leads to drop of detonation minimum pulse energy in the mixture. The mathematical models and numerical methodology for computer modelling of optical breakdown and laser-induced detonation in gas particle mixture are developed. Sub-models of optical breakdown on metal particle include heating of particle to boiling temperature, formation of vapour aureole around the particle, ionization of vapour aureole and development of electron avalanche, appearance of micro-plasma spots and their expansion, propagation of shock wave in the volume occupied by the particle. Laser-induced detonation in the mixture of hydrogen with flake aluminium particles is simulated based on Eulerian approach, and minimum pure energy of detonation is calculated for different parameters of laser pulse, mass fractions of particles and compositions of gas mixture. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.