In this paper, we obtain a complete rewriting system for monoid presentation of Schützenberger product of n groups, which is firstly defined in [G. M. S. Gomes, H. Sezinando and J. E. Pin, Presentations of the Schützenberger product of n groups, Comm. Algebra34(4) (2006) 1213–1235]. It gives an algorithm for getting normal form of elements and hence solving the word problem in this group.