聚乳酸（PLA）具有良好的降解性能、力学性能与加工性能，是当前有发展前景的生物基可降解材料。然而PLA仍存在耐热性能差等问题，限制其在耐热要求较高领域的应用与发展。PLA耐热改性已成为学术界与产业界共同关注的热点。文章介绍了PLA热变形过程与改性机理，系统阐述了PLA耐热改性的研究进展，包括物理共混改性、加工外场调控、成核结晶优化、化学长链支化等方法，重点论述了通过成核结晶优化提升PLA耐热性能的研究现状，同时总结了不同耐热改性方法的利弊。针对PLA材料的属性及其在实际使用中的需求，预测其未来发展方向将聚焦于高效环保、长效稳定、复合功能等方面。

Polylactic acid (PLA) is a biodegradable material with good degradability, mechanical properties and processing properties. However, PLA still has some problems such as poor heat resistance, which limits its application and development in the fields with high heat resistance requirements. Heat resistant modification of PLA has become a hot topic in academia and industry. In this paper, the thermal deformation process and modification mechanism of PLA were introduced, and the research progress of thermal modification of PLA was systematically described, including physical blending modification, processing field control, nucleation crystallization optimization, chemical long chain branching and other methods. The current research status of improving thermal resistance of PLA through nucleation crystallization optimization was emphatically discussed, and the advantages and disadvantages of different thermal modification methods were summarized. According to the properties of PLA material and its needs in actual use, it is predicted that its future development direction will focus on high efficiency and environmental protection, long-term stability, composite function and so on.