The invention discloses a method for detecting tiny faults of a satellite attitude control system and based on locally linear embedding (LLE). The method is based on a locally linear embedding method,and comprises the steps that firstly, historical data is enabled to have a zero mean value and a unified variance, then the number of neighborhood points is determined by a dynamic locally linear embedding (DLLE) method, a weight matrix W is reconstructed dynamically, then low-dimensional embedding Y of a sample set is found through the obtained weight matrix W, and two statistics of T<2> and SPEare further acquired; then an exponentially weighted moving average (EWMA) is solved by using an EWMA algorithm, an EWMA statistic range of normal data is used as a threshold value for judging whether to-be-detected data has faults or not, a mapping matrix A is further obtained and used for calculating the statistics of T<2> and SPE of online data, and the corresponding EWMA statistics is calculated; and finally whether the EWMA statistic of the online data is greater than a control limit or not is judged, if the EWMA statistic is greater than the control limit, the system faults are generated, and if not, the system is normal. According to the method for detecting the tiny faults of the satellite attitude control system and based on LLE, deficiencies of an original algorithm are overcome, and the detecting performance of the algorithm towards the tiny faults is improved.