Outdoor navigation technologies based on GPS and Beidou has been very mature. However, due to the weakness of satellite signal and refraction, they can’t satisfy the needs of indoor localization and parking area navigation in large commercial buildings. Most indoor localization technologies, such as Bluetooth and Wi-Fi, are based on active equipment. Due to the implementation cost, they can’t be widely deployed. In recent years, SLAM has been greatly developed and applied in the field of robotics and autonomous driving. For technologies such as stereo SLAM and Lidar SLAM require additional equipment, and meanwhile large scale computing will happen during point cloud matching, they are not suitable for civilian mobile usage. Considering the BIM technology, which can provide accurate 3D data of buildings, are widely used gradually, a real-time localization method combining monocular SLAM and BIM model is proposed to complete vision-based initial localization. First, we create the BIM model with the design drawings, extract the visible edge lines of model, and establish a 3D line feature database; then, intercept the key frames of the mobile camera, and extract the edge line and line feature descriptors from image, match the line features between key frames, triangulate the matched line segments, get the 3D line coordinate in first frame, mistake filter will be rolled out between multiple frames; finally, match the reconstruction result with line feature database form BIM model, register the initial position. This method can quickly and effectively perform the registration of monocular images and BIM models, get the initial position in complex spaces, and support the application scenarios such as indoor navigation, equipment maintenance, facility management, and construction monitoring.