To realize the task of tomato string-picking manipulator under the guidance of the obtained visual information, a visual servo control system for a seven-degree-of-freedom picking manipulator was designed. The visual servo control system consists of a parallel binocular camera, a 7-DOF manipulator, and a control system. The PC was adopted as the host computer, and the host computer control interface was developed based on Matlab software, which was to collect and process the image information. A STM32F103 microcontroller was used as the slave computer, which send PWM wave to control the joint motors in the instruction of host computer. The experimental results show that the visual servo control system has a 90% success rate in picking the static target, and the average picking time is 18s.The success rate for dynamic targets is 83%, with an average picking time of 22s.