Abstract: A mathematical model was developed to investigate the complex physical process of laser plasma interaction, adopting the PIC(particle-in-cell) approach to study the phenomena when heterogeneous ultra-short and ultra-high laser pulse propagated through over-dense plasma. Through the simulation of 3D laser pulse appearance in vacuum, it was found that a channel was formed due to the extremely large ponderomotive force associated with laser pulse. The lengthways electron velocity appeared in the position of the peak electric current intensity and the wave length became longer, which is coincident with the local oscillating electron heating mechanism basically.