Real-time kinematic relative positioning with its high precision features widely used in precision RTK mapping and high-precision navigation and other fields. In order to ensure the integrity of the system, base station sets multiple reference receivers. Therefore, it is necessary to select the best reference receiver. Under the conditions of multi-reference receivers, this paper presents integrity algorithm combined with residuals and an optimized selection method for multi-reference receiver to select the best receiver. Through several tests, it was verified that this method can avoid the risk of integrity, thus ensuring the positioning accuracy and positioning success rate of the rover