Phase-shift method based on domain analysis is not suitable for measuring step-changed object and always causes the accumulation of phase errors .Symmetric and asymmetric dual stair phase structure light coding methods for absolute phase retrieval were presented. The coding patterns of two methods are different. The width of the black and white fringes in symmetric coding patterns are equal,but not in asymmetric coding patterns. By the projection of binary coding structure light patterns, stair phase can be obtained with phase shift formula. During measurement ,on the basis of traditional sinusoidal fringe projection and phase shift method, high-precisionwrapped phaseis obtained. The stair phase can be used to determine corresponding ordersof wrapped phase.According to the order, the absolute phasecan be got. Gauge blocks are measured and root mean square error of two methods are 0.072mm.Both methods can effectively restore three-dimensional reconstruction for highly step-changed object.