Particle-in-cell (PIC) simulations of ultra intense laser beams boring into overdense plasma. The hole-boring or ignitor laser beam with intensity in the 10²⁰W/cm² penetrates the overdense plasma and generates MeV electrons, sending them into the core. There happens filamentation instabilities in energetic electron propagating through overdense plasma. In present paper, the energetic electron transport in overdense plasma by using three-dimensional PIC code is studied.