A non-submerged cavitation-erosion synergistic damage simulation device, system and method belong to the field of hydraulic machinery working condition simulation, including a sediment jet channel and a cleaning fluid channel in its periphery; high-speed sand-containing fluid is introduced into the sediment jet channel to form a central high-speed jet impacting the sample surface, high-speed cleaning fluid is introduced into the cleaning fluid channel to form a peripheral low-speed water curtain surrounding the central high-speed jet after being ejected from the annular steady flow pipe, and the peripheral low-speed water curtain impacts the sample surface to form a local liquid phase confining pressure zone together with the central high-speed jet. The present application not only realizes the true simulation of the actual working condition under non-submerged conditions, but also can adjust the flow and pressure of the cleaning fluid to adjust the cavitation number and cavitation collapse intensity around the high-speed sand-containing jet without changing the atmospheric environmental pressure, and quickly adjust the simulation test parameters.