A well collimated atomic beam plays an important role in laser focused Cr atom deposition. The simulations of one-dimensional (1D) transverse laser cooling of Cr atomic beam is performed with the Monte Carlo method. Taking into account the stochastic initial conditions of each atom, isotopes other than 52Cr, longitudinal velocity distribution and transverse divergence, the atomic beam cooled by laser is optimized and evaluated. The obtained results are consistent with experimental. In addition, with picking out the trajectories of isotopes other than 52Cr that are not cooled by the laser the center maximum value can be reduced by 9.3%, and the FWHM is increased by 11% of the transverse distribution.