Taking the application of the 3boom rock drilling jumbos in the advance pregrouting hole drilling during the construction of Xiang'an subsea tunnel in Xiamen as an example, the author presents the application technologies and application scopes of multiboom rock drilling jumbos in advance pregrouting hole drilling in fullyheavily weathered ground during construction of mined tunnels, by making comparison and contrast between multiboom rock drilling jumbos and other drilling machines. This paper can provide reference for similar projects in the future.