本论文针对80年代初引进的数控镗铣床电气系统正逐步进入老化期，故障频发，使用设备运行受限的现状，探讨了用现代数控机床电气系统对原来机电系统进行升级改造的技术方法，对企业提高设备的利用率，节约购买专用设备资金，提高经济效益具有较大的现实意义。 论文将目前成熟的光栅定位技术结合原有设备的结构特点，提出的以光栅尺代替原机床的同步感应尺来进行两个自由度的定位控制，能有效保证改造后机床的加工精度，采用圆光栅代替原机床工作台的四点定位提高了加工效率，通过控制手轮的应用加工过程中安全系数也有所增加。 针对BFKF150数控机床主要运行机构，选择了合理的数控系统、主轴驱动和主轴电机、进给轴驱动和进给电机、测量反馈形式等，从经济实用及车间加工需求考虑，选择了FANUC16i数控系统，它在该类型机床应用的最大优点操作简便灵活，运算速度快，可以实现系统4轴联动等。 改造后机床的自动化程度和加工精度有较大幅度的提高，具体尺寸加工精度由原来的10um提高到现在的3um；本论文将光栅定位、伺服变频等技术应用到机床主轴驱动的方案可以推广到其他相同类型价值高、机械系统性能稳定的进口机床改造中，在适应主轴转动功率及力矩的加工技术要求的前提下能节约成本，优化设备的使用效率。

.In this paper, the early 80's the introduction of CNC machine tools, presence of mechanical equipment in good condition, and the electrical system is gradually into the aging period, fault frequently, use of equipment operating limited status. Discusses the use of modern CNC machine tool electrical system to the old system upgrading technology, the purchase of special equipment for enterprises to save money, improve economic efficiency has great practical significance. The paper draws lessons from the professional techniques of combinative this factory is actual, put forward the special modification, there is relatively good results. In view of actual production requirement, the optical grating ruler is adopted instead of the original machine synchronous induction rule that after the transformation of the machining accuracy of the machine tool, using circular grating machine instead of the original four point positioning to improve the processing efficiency, through the control handle application process safety coefficient also increased. According to the BFKF150 numerical control machine tool, reasonable selection of NC system, the spindle drive motor and the spindle motor, feed drive and feed motor, a measurement feedback forms, from the economic utility and workshop processing demand, choose FANUC16i CNC system in the machine tool application types, it has the advantage of simple and flexible operation, fast operation speed, can realize 4 axis linkage system. After the transformation of the machining precision is greatly improved, the specific processing accuracy from 10um to 3um; intermediate frequency technology applied to machine tool spindle drive scheme can be extended to other types of machine tool spindle to rotate, in order to adapt to the power and torque of the processing technical requirements under the premise of cost savings, achieve the optimization effect.