Structured light 3D measurement technology is widely used in fields such as industrial inspection and medical imaging, but its measurement accuracy is often reduced due to the nonlinearity of the projector. In traditional phase-shifting methods, especially when combined with binary fringe projection techniques, a large number of fringe patterns are typically required to ensure measurement precision, which leads to low data acquisition efficiency. Focusing on how to improve measurement accuracy while reducing the number of projected patterns, this paper proposes a sixteen-step phase-shifting encoding method based on equally spaced binary fringes. The method generates binary fringe patterns with equally spaced distribution in advance, maps these patterns one-to-one to the corresponding sinusoidal intensity values within the same period, and then reconstructs the sinusoidal fringe through a weighted summation strategy. This innovative encoding approach enables each binary fringe to not only contribute information independently but also to be efficiently reused in the sixteen-step phase-shifting algorithm, thus significantly reducing the required number of fringe patterns and effectively improving 3D measurement efficiency. In the experimental section, the proposed method was quantitatively compared with the traditional sixteen-step phase-shifting method, the sixteen-step binary defocusing method, and the sixteen-step binary encoding method. The results show that, in terms of unwrapped phase accuracy, the proposed method achieved significant improvements, with the accuracy rates increasing by 71.42%, 87.17%, and 85.29% respectively compared to the other three methods, demonstrating its remarkable advantages in both enhancing measurement precision and reducing the number of projected patterns.