To fabricate uniform hollow glass microspheres (HGMs) for application in hydrogen storage, a sol-microemulsion-gel process combined with a T-shaped junction microfluidic technology was developed to fabricate monosized precursor gel microspheres. Precursor gel microspheres with monodispersity index less than 4% can be obtained based on the uniform reactions in the monosized sol droplets as micro-reactors, with monodispersity index less than 3%, generated by the microfluidic device. The results show that the precursor gel microspheres have uniform diameter, density, microstructure, composition and high sphericity. The monosized dried gel microspheres can be transformed into uniform HGMs, with high yield and quality for hydrogen storage, in a high temperature vertical furnace under the optimized operating condition.