To meet the control requirements of twin-roll strip casting mill， a new multi-process system platform was designed and developed. This process control system platform contains multiple processes. Each process has its own functionality and is relatively independent. This architecture enables the platform to have good flexibility and stabili- ty. The adaptive communication environment（ACE） was used in the platform development， which greatly reduce the difficulty of development and shorten the development time. The result of the long time test shows that this plat- form can run steadily， and was able to meet all of the online control requirements.