The utility model relates to a valve tower detection device that leaks based on refraction principle, light signal transceiver group installs on the lateral wall to the the optical signal transmitter of every light signal transceiver inter block lies in optical signal receiver's opposite and the optical signal transmitter and optical signal receiver lie in the not co -altitude of lateral wall, the optical signal transmitter and optical signal receiver of every light signal transceiver inter block all slope to install and the angle of slope is corresponding on the lateral wall, and messenger optical signal receiver only can receive the light signal that sends with the the optical signal transmitter of inter block, shelter from the not optical receiver of co -altitude and leak in getting into the casing when leaking to leading to the light signal because of refraction principle redirecting, making in the time of can't accomplishing light signal transfer between the optical signal transmitter and the optical signal receiver, alarm signal is sent on the warning backstage. The utility model has the advantages of simple structure, reliably, with low costs, the installation is safeguarded conveniently, can detect the circumstances of leaking in various degree rapidly and send the warning signal of different brackets.