Abstract: The technical challenges in the kinematic modeling and virtual-real interaction of hybrid assembly robots are addressed. A kinematic decoupling modeling method based on digital twin technology is proposed. Given the strong coupling characteristics of a hybrid robot system with 9 joint variables but only 6 degrees of freedom, a kinematic model for the parallel mechanism based on geometric constraints and a serial mechanism model using an improved Denavit-Hartenberg (D-H) method are developed. These models facilitate the dimensionality reduction and solution of a 9-dimensional nonlinear constraint equation system. In addition, a real-time rendering algorithm without a model is developed, utilizing OpenGL geometry shaders to dynamically generate the geometric shapes of the parallel mechanism's linkages, thereby solving the high complexity issues traditionally associated with pose calculation. A digital twin virtual-real interaction platform is built using QT and OpenGL, enabling high-refresh-rate synchronization between physical entities and virtual models. Experimental results show that the proposed method achieves a position deviation is no more than 0.1 mm, a posture angle error is no more than 0.05°, and an average system delay is less than 1 ms, providing a novel solution for digital twin applications in complex hybrid mechanisms.