The circular conveyor line adopts a 26 station horizontal circular structure layout, which can adapt to different seat cushion molds of various vehicle models. Mixed production of various products. The mold heating machine is placed at the corresponding workstation on the mold conveyor line. The power supply is introduced by a circular electric brush (slip ring), and the gas, water, and cables between the workstations are connected by hoses. The main transmission is chain driven, and the mold trolley conveyor line is driven by a variable frequency motor reducer through a driving chain. The mold frame on the small car adopts track opening and airbag locking, and the mold frame on the small car is closed by a mold closing machine, requiring safe and reliable operation. The compressed air used for the airbag is introduced through a high-pressure quick rotating joint. The operation mode of the production line mainly consists of cycle driving, automatic exhaust of the mold frame, mold frame unlocking, mold frame opening, manual cutting, cleaning, manual application of mold release agent, manual loading of auxiliary materials, horizontal reset of the mold frame, automatic filling, mold closing machine for mold frame closing, automatic inflation of the mold frame, mold frame locking, heating and curing cycle and other processes. The production line operates in a continuous cycle and has the characteristics of compact structure, easy operation, safety and reliability, smooth transmission, and high production efficiency. It can be applied to the mass production of various types of car seat cushions.