The utility model relates to an insulation protection device of photovoltaic low voltage ride through movement detection system, including voltage detection unit, voltage comparing unit and the protection output unit who connects gradually, voltage detection unit install in on the circuit monitoring point of photovoltaic low voltage ride through movement detection system, the current voltage of voltage detection unit real -time collection, with the signal carry for voltage comparing unit, voltage comparing unit with output the protective action node send for the protection system of high altitude photovoltaic low voltage ride through movement detection system. The utility model discloses effective equipment overvoltage that is directed against is monitored to send the trip protection signal, prevent that insulation of equipment from destroying the production loss, it also can adapt to to the low voltage ride through detecting system under the high altitude environment, can carry out the revise with voltage comparing unit's the operating value, satisfies different height above sea level area low voltage ride through detecting system insulation protection's requirement, and reduced the emergence of mishap, guaranteed the normal operating in power station.