The paper aims to study the online free switching of asynchronous motor control algorithm of packaging machine production line under different working conditions. Two high-performance control strategies FOC and DTC were selected as the switching object of the asynchronous motor algorithm of the packaging machine, and the common basis of the two algorithms was studied. A new FOC_DTC Algorithm was obtained as the transition algorithm of the switching system, which effectively solved the torque and current glitch caused by the online switching of the two control strategies. Furthermore, based on the hardware platform, the direct switching scheme and the reset PI switching scheme were compared with the proposed scheme. On the condition of meeting the requirements of all working conditions of the packaging machine, the hybrid FOC_DTC switching system had advantages over the above two schemes in switching response time, switching smoothness and switching efficiency, which improved the switching response time by 2% and reduced the switching torque peak by 30%. By using the hybrid FOC_DTC switching system, the packaging machine can switch the control algorithm of the power system motor online and real-time under different working conditions, which has obvious advantages over other schemes in smoothness and response time.