Abstract: In order to understand the expansion performance of shape memory screens in the downhole environments, a system for testing screen expansion performance was developed by simulating downhole environments based on its expansion principle, by which the expansion performance of the shape memory screen prototype was tested and analyzed the influences of the circulating fluid flowrate and temperature on the response temperature, expansion rate and expansion force. The results showed that the response temperature increased and the expansion speed decreased with the increase of circulating fluid flowrate. When the circulating fluid temperature was not lower than the initial response temperature, the expansion rate increased as the circulating fluid temperature rose, which showed that the influences of circulating fluid flowrate and temperature on the final expansion force were relatively minor. The test results can provide a test basis for designing a shape memory screen and its application in well completion.