In order to achieve the intelligent assembly of special-shaped thermal battery packs and solve the problem of low assembly accuracy in the assembly process, an assembly robot was designed and verified whether the robot can meet the assembly accuracy requirements of special-shaped thermal battery packs. The improved D-H parameter method was used to construct a kinematic model, and the end trajectory of the robot was analyzed through positive kinematics. The improved DE algorithm is used to solve the inverse kinematics, and the kinematics solution results are analyzed through simulation experiments. The average position error is 1.4×10–4 mm, the average attitude error is 2.4×10–4 degrees, the average number of solution iterations is 219.857, and the maximum angular velocity of each component should not exceed 3.5 rad/s. The designed assembly robot can meet the assembly requirements of special-shaped thermal battery packs, the kinematics solution accuracy is improved by two orders of magnitude, and the efficiency is improved by 72.5%.