As a complement to silicon-based photonic chips, lithium niobate thin film (LNOI) has become a research hotspot in the field of optoelectronic integration due to its outstanding nonlinear, electro-optic, acousto-optic, piezoelectric and other physical properties. On-chip integrated frequency multipliers, modulators, and filters based on lithium niobate thin films have been developed, but the on-chip integrated communication band light source is still in urgent need of development. Recently, researchers from Shanghai Jiao Tong University publicly reported for the first time that they designed, fabricated, and realized the laser output of a microcavity on a lithium niobate chip on a self-developed erbium-doped LNOI.