The metal filter element is studied in this paper which is mainly focused on the solution of silica pollution in reactor coolant loops, due to the consideration of easy damage and non-re-usability caused by traditional glass fiber filter element. High precision metal filter element is made of stainless steel metal fiber material, with good chemical compatibility, high filtration accuracy, large circulation, high strength, renewable, large sewage capacity, reduced resistance, good radiation resistance and other excellent performance. The metal filter element developed in our project has four kinds of accuracy: 0.1, 0.45, 2 and 5 μm. These four kinds of high-precision metal filters can be mainly applied to spent fuel storage pool cooling and purification system (PTR), chemical and volume control system (RCV), boric acid recovery system (TEP) and other reactor coolant loops related systems. The performance test shows that the filtration efficiency reaches more than 98%, the initial bubble point of the filter element with 0.1 μm accuracy reaches 3100–9600 Pa. The contaminant absorption capacity of the filter element with 0.45, 2 and 5 μm accuracy reaches more than 200 g/m2. The initial pressure drop of the filter element is less than 10 kPa, the rated axial load is more than 600 kPa, the flow fatigue resistance is more than 2000 times, and the rupture strength is more than 500 kPa, which is in line with the Technical Requirements of Nuclear Power Plant Water Filter Element. It effectively solves the technical problems and supply problems of the existing filter element in nuclear power plants (NPPs), in particular, the amount of silica precipitation is close to 0. The design and application of metal filter element in NPPs effectively reduce the production of solid waste, save a lot of economic costs and manual replacement of the filter element workload.