为了消除现有多频外差原理相位解包裹后存在的相位跳跃性误差，对多频外差原理相位解包裹方法进行了改进。利用双频外差原理进行部分条纹解包裹，然后利用相位与条纹节距之间的关系将解包裹后的相位转换为其他条纹的相位，使用转换后的相位对其包裹相位进行校正，得到展开相位。为了使展开相位不存在跳跃性误差，提出了解包裹过程中所需满足的一系列约束条件。模拟和实验结果均表明该方法简单有效，展开后的相位光滑无跳跃性误差，无需再次进行误差校正，相比现有方法时间效率提升30%以上。

In order to eliminate the phase jump error of existing phase unwrapping method based on multifrequency heterodyne principle, the improvement of the phase unwrapping method based on multi- frequency heterodyne principle is proposed. The partial fringes unwrapped phase is obtained by using the method of dual frequency heterodyne principle. Then the unwrapped phase is converted to other fringe relying on the relationship between the phase and the fringe pitch. After that, the wrapped phase is corrected by the converted phase, and the unwrapped phase is obtained. A series of constraints in the processing of unwrapping are derived in order to get the accurate and no jumped phase. The simulation and experimental results show that the method is simple and effective, and there is no phase jump in the unwrapped phase. The improvement of time efficiency is over 30% compared with the existing method.