In order to adapt to the customized needs of robots in different application, the construction technology of modular six-〖JP〗axis robots based on integrated joints was studied. Two types of joints, 14 type and 25 type, were developed, the mechanical and electrical communication interfaces were determined, and the joint performance parameters were obtained by testing. The six-axis robot configuration of the BRR wrist structure was selected, and the positive kinematics characteristics of the modular robot of this configuration were obtained by the MDH parameter method. Through analyzing the maximum load of the robot, the relationship between the arm span, acceleration and load was studied. Taking the designed 50 N load robot as example, the space motion trajectory of the maximum load condition was simulated, and the dynamic analysis was performed with ADAMS software to verify the load characteristics of each joint of the robot. Based on the modular robot technology, two types of modular robots were built, and the laser tracker was used to perform calibration experiments on the robots, and the robots were applied to the inspection operation scene. The results show that the modular robot technology based on integrated joints can be used to quickly realize the customized requirements for arm span and load.