To deal with the problems such as high complexity and low accuracy of redundancy detection, a model of redundancy detection based on control structure analysis is proposed and implemented. This paper predigests the complexity of control structure by establishing a compound node table for tokens, which reduces the complexity of redundancy detection, and then detects the idempotent operations, dead code and redundant assignment. Experimental results of the open source code of Linux show that this model can find redundant code accurately and also has a low time-complexity. With this model, it is very convenient for developers to detect and correct these kinds of defects, and thereby to further guarantee the software quality.