This paper proposes a two⁃dimensional constrained adjustment method with fused depth difference and a three⁃dimensional constraint adjustment method with additional depth by using the depth information from pressure transducer, in order to solve the problem of unstable vertical solutions in traditional underwater control network solutions. The considered problem exists in a control point coordinate that is determined based on a three⁃dimensional space distance intersection. Applying the former method with a given depth difference, the underwater control point coordinate can be determined by transforming the three⁃dimensional space intersection problem into a two⁃dimensional plane intersection problem and then constructing an adjustment model in the two⁃dimensional plane. Applying the latter method, the underwater control point coordinate is determined by solving the space distance equation combined with high precision observations and constrained conditions of the depth. We carried out experiments in Songhua Lake, and the experiment results show that the calculation precision of underwater control point coordinates is improved 2~5 times by applying both two methods. It implies that introducing the depth information into the calculation process of underwater control network and then constructing adjustment model can be helpful to improve the stability and precision of the three⁃dimensional solutions of the control network coordinates.%为解决传统水下控制网解算中基于三维空间距离交会确定控制点坐标存在的垂直解不稳定问题，借助压力传感器提供的深度信息，提出了融合深度差的二维平差方法和附加深度的三维约束平差方法。融合深度差的二维平差方法将深度差作为已知值，将三维空间交会问题转换为二维平面交会问题，在二维平面构建平差模型，确定水下控制点坐标；附加深度的三维约束平差方法将深度作为高精度观测值和约束条件，并与空间距离方程联合解算，确定水下控制点坐标。在松花湖水域进行实验，结果表明，两种方法均将水下控制点解算精度提高了2～5倍，说明在水下控制网解算过程引入深度信息构建平差模型，有助于提高控制网点坐标三维解的稳健性和精度。
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