The distribution function of relative velocity between two colliding atoms in three-dimensional space is obtained based on Maxwell velocity distribution function under thermal equilibrium condition. Considering this distribution function in the computation of laser-induced collision cross section, one laser-induced collisional energy transfer (LICET) process in Eu-Sr system both in weak and strong field is numerically calculated by integrating the motion equation based on the four-level model, and profiles of laser-induced collision cross section at given temperature are obtained. Impacts of relative velocity distribution on laser-induced collision process are analyzed by comparing the presenting numerical results with the former theoretical research. It is shown that although statistical distribution of relative velocity between two atoms has no impacts on the line shape of LICET spectrum, it has certain impacts on the peak value of collision cross section. The conclusions we came to in this paper are consistent with the theoretical predictions of former investigation, showing the validity of our numerical calculations.