The invention provides a BIM based plan graph and first view-angle split-screen synchronous display method and 
system. The method comprises loading and displaying a BIM stereo model; matching a navigation norm with a model bearing; generating a corresponding plane graph and placing a 
virtual camera; generating a corresponding first-person view-angle graph according to the camera position and view-angle information; displaying the view-angle bearing through the navigation norm visually, and providing a 
compass function; adjusting the 
view angle of the first-person view-angle graph according to user instructions, an adjusting the 
projection view angle direction of the 
virtual camera in the plane graph according to current view-angle data; and using the plane graph and the 
virtual camera projection as one portion and the first-person view-angle graph as the other portion to be displayed synchronously in a same screen. By means of the method and the 
system, a plane drawing and the first-person view-angle stereo graph are combined, the model bearing and the 
compass are combined, and accordingly, detail members can be observed and searched visually, the site actual 
engineering member and model member matching problem can be determined visually, 
construction management is facilitated, the requirement for the personnel technology is reduced, and even general workers can observe, 
record and search for the detail members according to images displayed on the same screen.