The invention discloses a water leakage detection method, a water leakage detection device and water leakage detection equipment based on a converter station valve internal cooling system. The water leakage detection method comprises the steps of: injecting a developer into internal cooling water of the converter station valve internal cooling system; detecting whether developer water vapor occursin the converter station valve internal cooling system after the developer is injected; and if so, prompting a water leakage situation occurred in the converter station valve internal cooling system.By means of the water leakage detection method, the water leakage situation can be prompted once the converter station valve inner cooling system leaks water.