The present invention provides a device for testing a self-expansion packer. The device comprises: a cylindrical body for holding a self-expansion packer, wherein the cylindrical body includes first ends of a liquid inlet and a liquid outlet and a second with a viewing port; a blocking piece configured to block the center tube of the self-expansion packer; a fixed piece connected at the cylindrical body configured to fix the self-expansion packer; and a decompression valve connected with the liquid outlet, wherein the liquid inlet is connected with a pressure test device. The device for testing a self-expansion packer can test the packaging capacity of a self-expansion packer in a high-flow condition.