Abstract: Microwave sulfur lamp is a kind of effective electrodeless electrical light. The lamp has the appealing property, which other lamps cannot be compared with, of producing a pleasant spectrum. First, working mechanism, features of microwave sulfur lamp are given in a brief introduction in the paper. Then key technology when manufacturing the microwave sulfur lamp is analyzed in detail and development direction of it is pointed out. The key technology is divided into three sections of waveguide system, bulb and power system. At last, the development state and broad application prospects of microwave sulfur lamp is summarized.