Abstract: In order to study the mechanical properties, thermal stability, dynamic thermomechanical properties, crystallization behavior and interfacial compatibility of hydrotalcite composites, Mg-Al hydrotalcite was prepared by coprecipitation method, and then calcined to obtain calcined Mg-Al hydrotalcite. The effects of temperature and time on the interlayer structure of hydrotalcite were investigated by variable control method. The hydrotalcite calcined at 300℃ (LDHs(300)) was characterized and tested by TG, SEM and XRD. The morphology and thermal stability confirmed that most of the interlayer water had been removed, and the layered structure was maintained without damaging its original properties. The calcined hydrotalcite was successfully intercalated with sodium dodecylbenzene sulfonate (SDBS) by FTIR and XRD. Then different surface modified hydrotalcite particles were added to polylactic acid/maleic anhydride grafted polypropylene (PLA-PP-g-MAH) by melt blending to obtain different composites. The results show that the properties of hydrotalcite composites modified by calcination are the best. The morphological analysis by SEM shows that with the addition of hydrotalcite to PLA-PP-g-MAH, the domain size of PP-g-MAH particles decreases significantly, and the PP-g-MAH phase has better wettability, resulting in higher impact strength, compared with pure PLA, it increased by 37.72%. From the rheological behavior, it is found that the rheological properties of calcined hydrotalcite composites are significantly higher than those of PLA. DMA shows that when calcined hydrotalcite is added to PLA-PP-g-MAH blend, the glass transition temperature (T_g) of PLA increased and the cold crystallization temperature (T_cc) decreased. DSC and POM show that the crystallization rate and crystallinity of calcined hydrotalcite composites are higher than those of PLA by 62.8%.