The invention discloses an integrated overhung composite insulator string and a method for printing a composite insulator string connecting metal tool by using 3D. The method comprises the following steps of: firstly, generating a three-dimensional CAD (Computer-Aided Design) model of a part in a computer, and printing the three-dimensional CAD model by utilizing a 3D molten-drop printing machine; then slicing up and layering the model according to a certain thickness, converting the three-dimensional information of the part into a series of two-dimensional profile information; melting down metal by using a crucible, and enabling the molten metal to flow out of a nozzle to form molten drops; then accumulating the molten drops layers by layer according to the two-dimensional profile information under the control of the computer so as to obtain a three-dimensional entity part or a part in similar shape. After the method is adopted, a ball-socket series of metal tools is shaped for once directly through the molten-drop 3D printing machine, the connecting cooperation is more reliable and more stable, secondary installation is unnecessary, and the production efficiency is improved; meanwhile, the efficiency of the site construction is provided, and a great influence to the construction of a high-voltage overhead power line is generated.