High-harmonic spectroscopy, an ultrafast all-optical technique initially conceptualized in atomic and molecular systems, has now emerged as a powerful platform for studying the structure and dynamics of condensed matter. Unlike that in the gas phase, solid-state high-harmonic generation relies on the fundamental response from high atomic density and periodicity, leading to interband transitions and coherent driving of electrons and holes in their respective bands. These mechanisms make high-harmonic spectroscopy particularly sensitive to the electronic band structure, topological properties and many-body correlations in condensed media. An advantage of high-harmonic spectroscopy over other spectroscopic methods is its ability to probe ultrafast phenomena, capturing femto- to attosecond dynamics of multi-band and strongly correlated electron interactions in solids. In this Review, we discuss the latest experimental and theoretical advances in ultrafast high-harmonic spectroscopy of solids and provide perspectives for future research in this field.

高谐波光谱学是一种最初在原子和分子系统中概念化的超快全光学技术，现在已成为研究凝聚态物质结构和动力学的强大平台。与气相不同，固态高谐波产生依赖于高原子密度和周期性的基本响应，导致带间跃迁和电子和各自能带中空穴的相干驱动。这些机制使高谐波谱对凝聚态介质中的电子能带结构、拓扑特性和多体相关性特别敏感。与其他光谱方法相比，高谐波光谱的一个优势是它能够探测超快现象，捕捉固体中多频带和强相关电子相互作用的飞秒到阿秒动力学。在这篇综述中，我们讨论了固体超快高谐波光谱的最新实验和理论进展，并为该领域的未来研究提供了前景。