Abstract: As an advanced aviation new technology, the GBAS landing system (GLS) of satellite navigation plays an important role in providing signal correction and enhancement service for airborne precision approach in terminal area, and in realizing the function of high-precision departure and precision approach of the whole system. GLS integrity is an important parameter of terminal area approach and landing guidance application, which is an important basis for reliability. However, at present, ordinary users only pay attention to the accuracy of navigation and positioning, and do not consider the reliability of positioning results. The airborne of navigation field has high requirements for the reliability of positioning results. Therefore, this paper studies and analyzes the integrity fault monitoring performance. A clock error adjustment strategy is proposed, and the effectiveness of the method is verified by simulation, the influence of interity fault removed and non-removal on positioning accuracy and integrity is given. It is proved that integrity fault monitoring can ensure the system performance, operation ability and safety performance of GLS to meet the expected requirements.