Abstract: The stringent attitude orientation accuracy demanded by the satellite flight omission motivate the development of recursive nonlinear filters for precise attitude estimation. This paperpresents the second order attitude estimator for the typical stellar inertial attitude determination system using the nonlinear filter based on the second order Taylor series approximation. In addition , the QUEST algorithm is efficiently combined with the attitude estimator as the compressing technique of multi vector observation information in order to simplify the update implementation . Performance comparison by computer simulation under the same conditions demonstrates that the second order nonlinear attitude estimator consistently performs better than the first order linear attitude estimator using the extended Kalman filter technology.