Analytical and numerical models of influence of docking process on combined spacecraft's initial attitude were developed. Based on the theorem of angular momentum with respect to total centroid, the general expression of numerical model for combined spacecraft's attitude angular velocity was obtained. By combining chase spacecraft's absolute motion with target spacecraft's relative motion equations, numerical model based on docking dynamics was developed. Finally, combined spacecraft's attitude angular velocity was contrasted with analytical and numerical models on different cases of single-error and multi-error. The results show that absolute error is within 0.07°/s and relative error is less than 10 percent between two models. Additionally, applicable phases of two models for engineering missions are presented.