The generation of high-order harmonics based on the interaction between ultrafast intense laser and matter provides a platform for studying the light-matter interaction in the non-perturbative region. It is also the main route to generating desktop extreme ultraviolet light source and attosecond pulse. The non-perturbative solid high-order harmonic involves the core content of ultrafast strong field physics, condensed matter physics, materials science, information science and other fields. Since it was first experimentally observed in 2011, it has rapidly become the research frontier of strong field physics and attosecond science. This review summarizes the research progress and important applications of solid high-order harmonics from the perspective of an experimentalist. Firstly, distinct characteristics are shown for solid high-order harmonic by comparing the dependence of harmonic yield and cut-off energy on driving laser parameters with gas high-order harmonic. Then, the progress of manipulation and application are highlighted for solid high-order harmonic, including the precise control of harmonic yield, polarization, space-time distribution through the design of target structure or laser field, as well as the application of solid high-order harmonic spectroscopy in the fields of material structure characterization and ultrafast electron dynamics. Finally, the future is prospected for the study of solid high-order harmonics.