Currently there are 6 mainstream oval foramen blocking materials, there can be categorized into traditional nickel-titanium alloy mesh and biodegradable materials such as polylactic acid, polyhydroxyacetic acid and polycaprolactone. 1. nickel-titanium alloy mesh. Amplatzer occluder is the first specialized oval hole unclosed occlusion occluder composed of nickel-titanium alloy mesh, but it is prone to metal allergic reaction. 2. Biodegradable materials. Representatives include the BioSTAR occluder made of non-magnetic nickel-cobalt-chromium-molybdenum alloy, the PLLA occluder made of PLLA, the DoubleUmbrella occluder made of a copolymer of polycaprolactone and propylene-caprolactone, the ChineseLantern occluder made of poly(L-cysteine) and PLLA, and the PDO occluder made of poly(p-dioxocyclohexanone). Biodegradable material occluders have fewer complications and good efficacy.