Aiming at the low qualified rate of module length due to the cumulative deviation of core size in stacking and welding process of lithium ion aluminum shell module in new energy automobile power industry, this design is put forward a strategy of double control based on length and pressure. In the design, module stacking and welding process could be controlled intelligently, and the qualified rate of module stacking at once was improved so as to ensure the stability and reliability of weld quality. The implementation of this length and pressure double control strategy can effectively reduce the mean time between failures(MTBF), to improve the Overall Equipment Effectiveness (OEE) and has a strong practical significance.