A novel combinated coding technology of Gray and phase-shifting is proposed. This coding algorithm combines advantages of Gray code and phase-shifting code. At first, Gray code is used to avoid the accumulation of error code. Then, the Gray code and phase-shifting code are combinated, they are respective as integral and decimal part of the combination code, a infinite space segments of the view space is divided by this intergration and a high coding resolution is achieved. Morever, a code compensation algorithm is developed to overcome the usual two codeing errors for acquiring a correct code. At last, the experiments show that this optical coding algorithm is effective and robust to three-dimansional reconstruction.