Bead foaming technology with double crystal melting peak structure has been recognized as a promising route to produce low-density foams with complex geometries. During the molding stage of the bead foams, the double peak structure generates a strong bead-to-bead sintering and maintains the overall foam structure. During recent years, polylactide (PLA) bead foaming has been of a great interest of researchers due to its origin from renewal resources and biodegradability. However, due to the PLA’s low melt strength and slow crystallization kinetics, attempts have been limited to the manufacturing methods used for expanded polystyrene. In this study, for the first time, we developed microcellular PLA bead foams with double crystal melting peak structure using a lab-scale autoclave system. Microcellular PLA bead foams were produced with expansion ratios and average cell sizes ranging from 6 to 31-times and 6.5 to 50 µm, respectively. The optimal generated high melting temperature crystals during the saturation significantly affected the expansion ratio and cell density of the PLA bead foams by enhancing the PLA’s poor melt strength and promoting heterogeneous cell nucleation around the crystals.