The invention discloses a Cu-Ni-Sn 
alloy belt foil for 5G communication and a preparation method thereof. The Cu-Ni-Sn 
alloy belt foil is prepared from the following 
raw material components in percentage by weight: 8.5-9.5% of 
nickel, 5.5-6.5% of 
tin, 0.2-0.5% of 
manganese, 0.1-0.3% of 
zinc, and the balance 
copper and impurities. The preparation method comprises the following steps: melting weighed 
copper and 
nickel, covering with wood 
charcoal, sequentially adding 
manganese, 
tin and 
zinc, stirring and dissolving after heating up to a temperature of 1300-1330 DEG C, slagging-off, covering withwood 
charcoal, standing and converting, slagging-off, and covering with wood 
charcoal; performing pull-
casting, homogenizing annealing treatment, face-milling, cold-rolling cogging, intermediate 
solid-
solution treatment, intermediate rolling, intermediate 
solid-
solution treatment and finished product rolling by adopting a reverse pushing-pulling and stopping blank pulling way, and obtaining foilwith a thickness being 0.04-0.1mm. Elasticity, 
wear resistance and 
corrosion resistance of a Cu-Ni-Sn 
copper alloy in the prior art are kept, and meanwhile, the Cu-Ni-Sn alloy belt has good forming property, relatively 
high conductivity and excellent shielding performance, can realize industrial production of the Cu-Ni-Sn alloy belt foil for 5G communication, replaces import, fills up the domesticblank to promote copper 
processing industry development needs of the current stage.