This paper describes the design and construction of a 6- DoF nursing robotic arm based on DMJs, aimed at addressing the nursing transfer scenario. The structural parameters and performance indicators of each part of the robotic arm are provided. The transmission principle of the modular joint arm is analyzed and its kinematics are decoupled. The modified DH method is utilized for kinematic modeling of nursing robotic arms. A nursing robotic arm digital twin system is built on Unity3D, enabling bi-directional information interaction and mapping between the real and virtual system. We conducted experiments on both the physical robot and the digital twin system using pre-determined lifting motion trajectories. The results demonstrated the robot’s proficiency in completing nursing transfer tasks and the accuracy of the virtual-physical mapping in the digital twin system.