The invention discloses a low-melting-point liquid metal alloy and a preparation method thereof, and belongs to the field of liquid metal materials. The liquid metal disclosed by the invention has the characteristics of being copper-bearing and low-melting-point, and is composed of the following components in parts by mass: 20-50 parts of gallium, 5-10 parts of bismuth, 5-10 parts of indium, 1-5 parts of thallium, 1-5 parts of tin and 0.01-1 part of copper. The liquid metal can be widely applied to manufacturing for products in some low-temperature environments.