Driven by regulations and driving pleasure, electrification will have a huge impact on future automotive powertrain technology. At present, most hybrid powertrain systems use a hybrid expansion scheme based on traditional gearboxes, that is, use existing gearboxes and make adjustments to make them suitable for motor drive. A good example of this hybrid expansion program is Volkswagen's DQ400e gearbox. In this case, a module is placed between the engine and the DCT to enhance the functionality of the standard DCT gearbox. Another case is ZF's 8P70H gearbox, whose bell-shaped housing is extended to support the motor that replaces the torque converter. The strength of a clutch in the gearbox is improved and can be used for vehicle start. This hybrid expansion solution has several advantages due to its reusable parts and production lines, reducing the workload of development. As the output of hybrid powertrain systems continues to grow, the requirements for functionality, weight, layout, cost, and higher efficiency drive the development of hybrid powertrains towards specialized and more optimized solutions, resulting in hybrid transmissions. At present, the hybrid models of domestic and foreign auto manufacturers adopt this special transmission scheme, such as Toyota and SAIC. However, electric drive gearboxes dedicated to hybrid power require high technology and large investment to support development, and material costs have advantages in larger batches.