A method of pitch-variation moiré fringes is proposed to realize the temporal phase unwrapping for three-dimensional profilometry. On the basis of the principle of moiré pattern,we achieve variable spatial frequencies of fringes in a moiré pattern by rotating two gratings. Furthermore a five-point fitting method is used to automatically compute the central position of side-lobe spectrum of the moiré fringes. Finally,a generalized temporal phase unwrapping algorithm is intro-duced to process the three-dimensional reconstruction. The theoretical analysis and experimental results show the validity of the proposed method.