We have developed the two and half-dimensional electromagnetic relativistic electron and mobile ion cloud-in-cell(CIC) code. Mechanisms of the fast ignition and interaction of ultra-intense and ultra-short pulse laser withplasma are analysed theoretically and simulated numerically using the CIC code. The strong flows of relativisticelectrons and the form of the channel are observed. The results show that the superhot electron temperature isabout MeV to tens of MeV, and the boring velocity is 0.05c - O.1c with c being the light speed. Some preliminaryscale laws are obtained. This simulation quantitatively reproduces the experimental results at early and longtimes.