Abstract: Satellite internet provides positioning, navigation and timing services for the whole world based on the Global Navigation Satellite System (GNSS), but the data containing users’ location information will be leaked during GNSS cooperative positioning process, which poses a threat to users’ privacy security. To address the current privacy-protection challenges in GNSS cooperative positioning systems, this paper proposes a differential privacy-based cooperative positioning method for GNSS systems. The method first generates the perturbed position and randomly selects one to calculate the positioning collaboration data under the premise of satisfying the privacy budget, so as to prevent the user’s location from being leaked during the collaboration process. The experimental results show that the proposed method can effectively protect user location privacy while guaranteeing real-time and accurate positioning service, which provides a theoretical reference for the research of GNSS cooperative positioning information security.