During the laser welding of the aluminum shell of the lithium-ion battery for electric vehicles, due to the high temperature, the gas in the welding area is easy to be converted into steam, thus forming pores. For this reason, a method of controlling porosity in laser welding of lithium ion aluminum shell of electric vehicle is proposed. The influence of laser welding process parameters (laser welding line energy, pulse frequency, and laser duty cycle) on the weld porosity of the lithium-ion aluminum shell of electric vehicles was analyzed. The approximate function of the model was obtained using the multi-output Gaussian process to build the parameter model for controlling porosity in laser welding of the aluminum shell of lithium-ion batteries for electric vehicles. The model was solved using the improved Ant colony optimization algorithms based on the direct learning mechanism to obtain the optimal solution for welding process parameters and achieve control over welding porosity. The experimental results show that the pulse frequency of the proposed method is 47 Hz at 350 s, and the operation time is only 20.97 s, which shows that the proposed method has good control effect and stability, and can realize the control of pores in the laser welding of lithium ion aluminum shell of electric vehicles, with high efficiency.