Traditional subtractive clustering algorithm time complexity is pretty high
and it doesnt have the characteristic of distributed processing. Therefore
it is not suitable for the processing requirement in big data environment. This paper proposes an improved subtractive clustering algorithm which is based on Hadoop. It applies multiple MapReduce processes to implement the parallelization of subtractive clustering in solving neighborhood radius
initializing density index
updating density index and dividing the data records. Experiment demonstrates that comparing to the traditional serial algorithms
the proposed improved algorithm can indeed cluster the big data fast and has good stability and expansibility.