In general, number of joints are increased to diversify robot motion, and these joints are composed of servo motor which generates mainly rotational force, decelerator, and encoder which controls servo motor’s angular motion. Increasing the number of joints means larger cost burden for the robot. In this study, we intended to develop multi-joint robot that maintains the precision of the robot while increasing output power, reducing production cost and reducing the size of joint itself by replacing general servo motor joint with hydraulic actuator joint for the 3- axis that control position among the 6- axis joints that drive robot. This study is also intended to secure structural stability of hydraulic actuator joints which are the key modules of multi-joint robot through drive dynamics and life span analysis.