Abstract: Described in detail here is the composition of the automation system of the Accu-Roll pipe mill line located at No. 5 Pipe Mill, Pangang Group Chengdu Seamless Steel Tube Co., Ltd. To further ensure the reliability, suitability and consistence of long-term trouble-free running of the said automation system, additional functions have been provided, namely software-based intelligence control instead of hardware-based control, auto-fault diagnosis and auto test-run. Furthermore, the power supply system has been also improved. Thanks to the above mentioned technical actions, the technological level of the said automation system has been enhanced, having brought about significant economic benefit.