In recent years, many wearable motion support system have been developed in a variety of applications. We have developed the wearable walking support system to support the part of the joint moment of the human body estimated based on the human model on the sagittal plane. However, when we consider the support of any motion in daily life, it is desirable to estimate the joint moment in three-dimensional space. In this paper, to support system the motion in daily life, we extend the human model on the sagittal plane to the one in three-dimensional space, and explain a method for estimating the joint moment in three-dimensional space.