Volcanoes are a window for humans to explore deep magma systems. From a global perspective, crystal-poor and melt-rich volcanic rocks (especially basalt and rhyolite) are mainly exposed all over the earth, while crystal-rich felsic volcanic rocks exposed around many calderas. The felsic crystal-rich volcanic rocks can be mainly divided into two types: one type is the volcanic rocks with homogenous composition and crystal contents; the other type is the volcanic rocks with zoned composition and crystal contents. The crystal-rich volcanic rocks erupted due to the cold stored crystal mush was remelted, reactivated, and remobilized after being repeatedly recharged by hot magma. The composition of the preexisting materials in the reservoir constrained the type of crystal-rich volcanic rocks formed by reactivation. The existence of crystal-rich volcanic rocks can well explain the contradictory phenomenon that the magma reservoir has a long life, but the process of magma accumulation and crystallization is rapid. Although the research of felsic crystal-rich volcanic rocks has made obvious progress in recent years, there are still many problems to be solved, such as the origin of porphyritic lava, how to reveal the reactivation of crystal mush, the relationship between crystal mush reactivation and volcanic eruption, the time scale of magma recharge and crystal mush reactivation, etc. Further research on crystal-rich volcanic rocks will promote the understanding of the mechanisms of melt evolution, migration, and shallow accumulation and eruption, providing more information for establishing a more comprehensive model of felsic magma evolution.