Spatial structures have been used widely for transmission in mechanical engineering, such as a universal jointed shaft in drilling process or a slider-crank linkage in compressing process. Solving kinematic problems in those mechanisms is quite complex. Some solutions have been proposed with both strong and weak points. This study proposed a new method to analyze kinematic problems for mechanisms using orthographic projection. Kinematic analysis of spatial structures could be carried out easily by setting up associative equations as well as simulating the motion of these structures. The simulated results were validated by Matlab software.