Abstract: The spacer of NHR-200 is composed mainly of the inner,outer and cornual strips which are ranged in egg-crate of 12×12-3.First,the pre-distortion of three kinds of three-arc springs on reactor working condition and their related clipping-force ranges are analyzed in this paper.Secondly,the mechanical experiments of 1:1 prototype,such as the load-distortion experiments,which the load and distortion are respectively measured by strain gauge and displacement sensor,of three kinds of springs,rigid supports and the spacers in two different directions are carried out on a special experimental facility.The experimental results show that the spacer can completely meet the design demands of mechanical properties of the fuel assemblies in NHR-200.