The invention is a method for rapid identifying genetic sex of tongue sole, comprising rapid extracting DNA of tongue sole, designing and synthesizing of LAMP specific primer, establishing a LAMP reaction system, detecting of LAMP reaction products and identifying genetic sex. By female specific molecular marker sequence of tongue sole, the invention designs specific primer, performs transitory nucleic acid amplification under constant temperature, the genetic female individual produces specific DNA fragment, while the male individual does not produce such DNA amplification product. The invention creates a LAMP method for rapid detecting genetic sex of tongue sole for the first time, can be used in culture farm, and the testing operation can be finished within 2.5h. The invention has the characteristic of being advanced, rapid, specific, precise, sensitive, simple and in no need of large-scale instruments, thus providing a new technological approach for fish sex detection and control. The invention has important application value in control of tongue sole sex and production of unisex fry, and wide application prospect in identification of genetic sex of other fish species and research of sex control.