Abstract: One of the most fundamental issues in DNA computing is how to improve the Signal to Noise Ratio through effective encoding in the process of DNA computing. This paper propose a new DNA encoding filter selection algorithm based on Rough Set and Fuzzy theory: reduction the encoding standards expected through the Rough Set theory and filter the DNA encoding sets using the negative filter selection algorithm based on Rough Set, gain the initial encoding sequence library and construct an optimized method for DNA encoding selection algorithm based on Rough Set theory. Experimental results indicate that the method can effectively weaken the complexity of DNA encoding caused by the invalid constraint conditions, provide a new tool for the DNA encoding selection algorithm.