With the increasing complexity of the product, designers have to spend much time and money in product design. On the way to find the best solution, various simulation tools, such as CAD/CAE software, have been introduced into design process to simulate specified characteristics. In order to drive all these tools to work as a united simulation system, a kind of distributed computing model must be designed to control the iteration of simulation process. This paper presents a series of transfer subroutine modules (TSMs) and corresponding control strategies to realize conditional control, feedback control, comparative control and recursive control etc., so that a collaborative simulation environment can be built. Based on the TCP/IP protocol, multiple simulation agents have been realized to integrate corresponding software and drive all the design modules to operate automatically. Finally, an example of distributed simulation is given based on this distributed computing model.