Dynamical optimization model regarding distribution cam mechanism in internal combustion engine is built. Based on immune genetic algorithms and MATLAB, optimization programs concerning the model are made and the simulation is conducted. Compared with original design, the simulation results show that plentiful coefficient increases by 1.24%, dynamical maximum positive acceleration lowers by 0.87% in ascending and increases by 5.23% in descending. The maximum negative acceleration decreases by 5.93%. All these make system dynamical velocity and...