As a biodegradable polymer derived from biomass resources, polylactide (PLA) exhibits tremendous potential to replace conventional petroleum-derived and non-biodegradable polymers because of its extraordinary transparency and favorable mechanical strength, etc. However, the engineering applications of PLA have been significantly hindered by its poor toughness and insufficient heat resistance. Blending PLA and elastomer is an economic way to improve the toughness, but a substantial elastomer content of 15-20 wt% is required, which in turn leads to a considerable loss in the heat resistance. In this work, taking poly(L-lactide)/poly(D-lactide)/poly(ethylene-methylacrylate-glycidyl methacrylate) (PLLA/PDLA/E-MA-GMA) blends as an example, we report a facile and robust strategy to fabricate super-tough and heat-resistant PLA blends via stereocomplexation and reactive blending. Very interestingly, the results shows that the formation of numerous stereocomplex (SC) between PLLA and PDLA is very effective in enhancing the heat resistance of PLA/elastomer blends. The highest heat distortion temperature (HDT) can reach to 200 °C, which is comparable to some petroleum-based engineering plastics. More importantly, during the reactive blending, some PLLA/PDLA chains are chemically grafted onto the backbone of E-MA-GMA copolymer and thus impart the blends with excellent melt stability. As a result, the PLLA/PDLA/E-MA-GMA blends with high degrees of SC crystallinity can be fabricated by injection molding, without subsequent thermal treatment. Furthermore, the blends display superior chemical/hydrolytic resistance to neat PLA. Overall, this work could provide a universal platform for designing high-performance PLA materials.