To explore the changing rule of morphology and physical quantity of the droplet in the micro-explosion process of single gelled fuel droplet, numerical simulation study of the micro-explosion process of JP-8 metally gelled fuel droplet was carried out by smoothed particle hydrodynamics (SPH) method. The problem of severe changes of density gradient and smoothing length gradient in the process of bubble expansion was solved by introducing the full variable smoothing lengths SPH method. The elastic gelatinizer membrane was simulated by the modified JCD (Johnson-Cook Damage) strength model. The growth, expansion, broken shell, jet etc.processes for internal bubble in the micro-explosion process of gelled droplet were simulated. The variation characteristics of internal pressure of droplet and stress of gelatinizer membrane in the bubble deformation process were obtained. The changing rules of droplet′s radius, pressure, tensile stress and surface tension etc. physical quantities in the micro-explosion process of gelled fuel droplet were explored. The numerical simulation results show that the droplet′s volume expands gradually and pressure increases in pulse as time goes, and gelatinizer membrane breaks and the droplet′s volume decreases rapidly when diameter ratio D/D₀ reaches 1.4; For the multi-bubble gel droplet, the large bubble expands faster than the small bubble, and generates larger pressure on the wall, leading to the gelatinizer membrane fractures near the big bubble, and the rupture time is shortened compared with the single bubble. The numerical simulation results are in agreement with the experimental ones, which reveals the inherent mechanism of the droplet micro explosion process and verifies the effectiveness of the SPH algorithm in solving such problems.