The work aims to design a set of test tube automatic transfer device based on manipulator according to the operating requirements of the test tube transfer mechanism in the automatic medical inspection assembly line. With the programmable controller based on FX2N PLC as the control core, the automatic operation of the test tube transfer was realized with other hardware devices. The design of mechanical structure design, the work content planning and the software and hardware design of the control system were emphatically described. With 11 μm positioning accuracy of the test tube transfer device designed and developed, the automatic transfer of the test tube could be completed. The device is featured by reasonable mechanical structure design, stable operation, high working efficiency and accurate positioning. The ingenious combination of hardware system and software system gives a full play to the powerful functions of PLC controller and touch-screen man-machine interface, which can be used in automatic medical inspection assembly line, instead of the manual loading and transfer of the test tube.