In this paper, a new three translational degrees of freedom (DOF) compliant parallel micromanipulator (CPM) is proposed, which has an excellent accuracy of parallel mechanisms with flexure hinges. The system is established by a proper selection of hardware and analyzed via the derived pseudo-rigid-body model. In view of the physical constraints imposed by both the piezoelectric actuators and flexure hinges, the CPM's reachable workspace is determined analytically, where a maximum cylinder defined as an usable workspace can be inscribed. Moreover, the optimal design of the CPM with the consideration of the usable workspace size and global dexterity index simultaneously is carried out by utilizing the approaches of direct search method, genetic algorithm (GA), and particle swarm optimization (PSO), respectively. The simulation results show that the PSO is the best method for the optimization, and the results are valuable in the design of a new micromanipulator.