Indoor navigation turning calculating method and system

The invention provides an indoor navigation turning calculating method and system. The method comprises the following steps: taking a preset distance as an interval on a navigation path, and sequentially extracting geographical location information of a plurality of path nodes; converting the geographical location information to display points on a physical coordinate system, namely a navigation equipment display screen, and displaying; in three adjacent display points, sequentially calculating a first included angle between a first straight line that a first display point and a second display point are connected and a horizontal axis of the physical coordinate system as well as a second included angle between a second straight line that the second display point and a third display point are connected and the horizontal axis of the physical coordinate system; judging that whether the third display point belongs to a turning display point by virtue of the first included angle and the second included angle, whe