We report on the results of molecular dynamics simulations of nanowelding at high temperature between the gold electrodes and single-walled carbon nanotubes (SWNTs). We find that SWNTs with gold nanoclusters absorbed on their tips can build an excellent welding contact with gold electrodes. First, gold clusters are placed on open tips of SWNTs and are annealed at 1100 K. Gold atoms enter into the SWNTs and a shell-like helical structure inside the SWNTs and an amorphous structure outside of the SWNTs. Furthermore, the SWNTs absorbed with gold cluster are then placed on surfaces of gold electrodes. After annealing at high temperature, gold atoms absorbed in the SWNTs are redistributed on the surface of the gold electrodes and form excellent welding contact with the electrodes. The best annealing temperature for welding is about 800 K.