Femtosecond laser has been widely used in elaborate processing and micro/nano manufacturing field due to its ultrashort pulse width and extremely high peak intensity. At present, the fabrication of flexible devices by laser direct writing has attracted much attention. The following four research directions based on laser direct writing technology are reviewed: 1) laser direct writing microball lens for wide angle imaging; 2) laser fabrication of Au/reduced graphene oxide micro supercapacitor; 3) preparation of multilayer supercapacitor on polyimide substrate; 4) laser fabrication of capacitive biosensor. Relevant research work of our group is introduced at the same time. This paper provides a reference for the research, application and future direction of the micro/nano device fabrication by laser direct writing.