With the increasing requirements for satellite navigation and positioning technology, the detection and identification of faulty satellites has become the focus of attention. The existing satellite navigation receiver autonomous integrity monitoring technology is based on pseudo-range observation measurement and implementation, and does not consider the original navigation signal still contains a wealth of new information that is not used for integrity monitoring. Therefore, this paper proposes a receiver autonomous integrity monitoring algorithm based on the original navigation signal to realize the detection and elimination of faulty satellites. This paper proposes an integrity monitoring algorithm based on the original navigation signal. This method firstly expresses the signal to noise ratio of the channel by using the original navigation signal; secondly, construct a new covariance matrix by using signal to noise ratio and channel bandwidth; then use the covariance matrix to derive the PVT covariance matrix, and then obtain a new test statistic; finally, the detection and identification of the faulty satellite is carried out. Tests show that the method can detect the influence of slight noise more sensitively; at the same time, the method can detect any event that may affect the PVT, so that an alarm can be issued to inform the user of the occurrence of an abnormal fault. Therefore, the method not only applies the original navigation signal to the integrity monitoring, but also improves the sensitivity of the integrity monitoring, thereby greatly improving its performance.