Aiming to achieve the harvesting of various types of fruits and vegetables, a multi-segment independently controlled flexible picking gripper driven by electrorheological fluid (ERF) was designed based on a human-finger-inspired structure. The gripper adopted a modular and integrated design, and the flexible fingers were directly driven by micro-pumps. The finger comprised three multi-chamber flexible joints, each containing an embedded ERF microvalve. The electrorheological fluid served as both the actuation and working fluid. By leveraging its tunable rheological properties through the coordinated operation of the microvalve array, independent bending deformation of each joint was achieved. A comprehensive study was conducted on the control principles of the multi-segment finger. This involved developing theoretical models for the current-controlled microvalves, the deformation of the flexible joints, and the finger's overall kinematics, all of which were validated experimentally. The models quantified critical performance metrics, such as the microvalve threshold pressure, the normal output force and deformation as functions of air pressure, and the finger's kinematic workspace. Furthermore, a two-finger picking gripper prototype was fabricated, and an experimental platform was constructed to conduct grasping and picking tests on various fruits and vegetables. Results demonstrated that the finger exhibited smooth, flexible, and diverse movements. The integrated mierovalve system enabled a single input to produce human finger-like multi-modal deformation, the gripper offered a larger envelope workspace and superior shape adaptability. A maximum joint bending angle of 121° and a normal output force of 2.3 N were achieved. The two-finger picking gripper featured multiple grasping modes, including enveloping, pinching, and clamping, exhibiting excellent adaptability to different object shapes, which was suitable for harvesting small and lightweight fruits and vegetables.