The quaternion attitude algorithms are studied in this paper. The scale error, skew error and drift error for algorithms of different kind are clearly described by using US fraction of attitude matrix. 该文对姿态计算四元数方法进行了研究.通过对计算姿态矩阵的US分解,清楚地表达了不同算法的标度误差、歪斜误差和漂移误差;