Abstract: The radioactive radial uniformity of ⁶⁸Ge line radioactive sources is a critical quality parameter. The radioactive source scanner with linear scanning function is developed by making use of high-speed pulse counters, high-speed pulse output ports, and the powerful instruction system of Siemens S7-200 series programmable logic controller (PLC). A computer used as a host computer of the instrument communicate with the PLC by point to point interface (PPI) protocol, The instrument with functions of data collection, ransmission, displaying, saving, motion control and instrument parameter settings, can be used to measure the radioactive radial uniformity and total acrivity of line radioactive source. The advantages of Using the PLC to develop nuclear instrumentation are development speed, strong anti-interference ability, and low-cost.This paper mainly describes the control system implementation and feature of the instrument.