Abstract: Based on the theory of MONGE descriptive geometry, the paper aims at the complexity of three dimension space angles, be analyzing and inducing of tarries space relations, according to the common features of its forming environment, the three dimension space angles are scientifically divided into three types , essential type, line-plane type and line-line type. According to the feature of varies types, makes the concerned theory complementally and perfect. By using the concept of “Walk-direction” of single element, establishes the geometry model of line-plane type “Plane area-sharing law(Walk direction law)” and line-line type “Walk-direction associative law”. The paper comprehensively reveals the intrinste law of space angle calculation, derives the common function expressions which use two dimension method, and calculation software is programmed also. The practice of large quantities of static calculation and dynamic analyze, optimization proves that the established model has the compatibility to the existing theory and methods, and also has the features of high calculation speed, high accuracy.

Key words: Automatic calculation, Space angle