The invention relates to nano-metal ink capable of being cured at low temperatures, a preparation method therefor and an application of the nano-metal ink. The nano-metal ink contains the following ingredients: nano-metal particles and an ink carrier, wherein the nano-metal particles are a mixture of nano-indium and nano-silver, and the ink carrier contains the following ingredients: a solvent, a dispersant, a surfactant, a humectant and a tackifier. The nano-metal ink prepared by the preparation method integrates the advantage, i.e., low curing temperature of the nano-indium and the advantage, i.e., low surface resistance of the nano-silver. Through combining the two kinds of nano particles, not only can the problem that curing and sintering temperatures are too high be solved, but also the condition that sintered circuits have excellent electric conductivity is guaranteed. In addition, the preparation of the nano-metal ink, the nano-indium and the nano-silver has no especially harsh requirements on solvents, reagents and experimental conditions, and the operation is easy and feasible. The ink is especially applicable to the manufacturing of flexible electronic devices with relatively high requirements on electric conductivity.