The invention belongs to the technical field of material chemistry, relates to conductive ink, and particularly relates to nano copper-tin alloy conductive ink and a preparation method and usage of the nano copper-tin alloy conductive ink. Nano copper-silver alloy is replaced by nano copper-tin alloy to be used as conductive filler in the conductive ink, sintering temperature of the conductive ink is lowered, and when the nano copper-tin alloy conductive ink is compared with nano copper-silver alloy conductive ink, antioxidant capacity of the conductive ink during sintering is improved, mechanical property and solderability of a conductive circuit formed after sintering of the conductive ink are improved, and the problem of silver ion migration is avoided. Further, since rare earth metal elements are doped in the nano copper-tin alloy, grain boundary of the nano copper-tin alloy is increased, electron scattering power is increased, and conductivity is improved as compared with that of nano copper alloy. On the other hand, tin is much cheaper than silver, so that raw material cost of the nano copper-tin alloy conductive ink is reduced.