KJJ220 encapsulated and intrinsically safe optical fiber ring network switch for mining can be used as an underground backbone ring network switch or an underground branch switch. It includes the built-in two-layer 1G network management switch and encapsulated power module. It has rich interfaces and strong access capabilities, including 1G optical ports, 100M optical ports, 100M electrical ports, 485 ports, etc. If interfaces are insufficient, the switch can be expanded by plugging and unplugging its board, in order to provide abundant accesses for underground devices and meet the requirements of underground smart devices for interfaces.