As simulation softwares are playing an essential role in communication theory experiment, it is necessary that a platform should include sufficient simulation blocks, test cases and detailed help files. This paper presents a method for the usage of SCICOS in communication theory experiment, and as an example, the 2FSK modulation is described to demonstrate this method. And the paper proposes a method of secondary development in communication systems simulation based on SCICOS. This method is applied to a novel platform, which aims to provide more efficient and convenient experimental environment by developing a toolbox-SCICOM. Furthermore by setting up a baseband transmission system- the implementation of this method is described in detail. Practice shows SCICOM has a good practical application value.