In this paper, we proposed a piecewise step phase coding method to solve the error codes occurring in the three-dimensional (3D) shape measurement method using the phase coding technique in the phase unwrapping for the wrapped phase of high-frequency fringe. The first step codewords were used to encode the order of the second step codewords. After two groups of phase coding fringes were projected for the recovery of two sets of codewords, two extra misaligned Gray code patterns were projected to obtain two codewords shifted by half period from the two sets of codewords, respectively. By taking advantage of the mismatch between the misaligned and original codewords, we selected different codewords for complementary decoding. Therefore, more reliable fringe orders were obtained for 3D reconstruction. Experimental results reveal that the proposed method is robust in decoding codewords and can label more fringe periods than the complementary Gray code method using the same number of projected auxiliary patterns. Furthermore, the proposed method accurately reconstructs 3D shapes of complex objects with denser high-frequency sinusoidal fringes.