Cable-Driven Parallel Robot has many advantages. However, the problems of cable collision between each other and environment, the lacks proper structure and non-positive cable tension prevent the spread of them. Therefore, connecting a serial manipulator to mobile platform improve the ability to object manipulation. This paper investigates the multi-objective optimization structure design and comparative study of spatial constrained and suspended cable-driven parallel robot. By install serial manipulators possess a full hybrid robot’s features. The workspace volume, kinematic stiffness and sensitivity are three sets of optimization criteria. The workspace volume calculated by a novel approach of combination constraints as prevent cables collisions with each other, cable collision with moving platform, uncontrollability and singularity of the robot. First, examine range of the forces and torque reaction of the serial manipulator to moving platform. Then, the evolutionary optimization genetic algorithm use for the multi-objective optimization of constrained and suspended spatial cable-driven parallel robot structure to achieve proper Pareto front confrontation. The Pareto front reconciliation of these three criteria will be discussed. The constrained and suspended optimize by same criteria will compare in the same conditions. It is verified that the constrained structure significantly reduced actuation energy for manipulate a serial robot, supply greater workspace and manipulability. The result of this study used for manufacturing and development of a prototype spatial cable-driven parallel robot (RoboCab).