To operate a double-column CNC lathe, you need to follow the steps below:

1. Preparation:
a. Make sure that the double-column CNC lathe is in the correct operating state, including power on, machine cooling system running normally, etc.
b. Inspect and install required tools, fixtures and workpieces.
2. Start the machine tool:
a. Turn on the power to the machine and make sure that all operator panels and display screens are functioning properly.
b. Start each main system of the machine tool, such as hydraulic system, cooling system, etc., according to the instructions in the machine tool operation manual.
3. Load the processing program:
a. On the operation interface of the CNC system, select the corresponding processing program and load it into the control system of the machine tool.
b. Make sure the loaded machining program matches the workpiece requirements and tool parameters.
4. Set the workpiece coordinate system:
a. Use the coordinate system setting function on the machine tool operation interface to correspond the coordinate system of the workpiece with the coordinate system of the machine tool.
b. According to the processing program and the requirements of the workpiece drawing, set the origin of the workpiece and the corresponding offset.
5. Install the tool and fixture:
a. According to the process requirements and the needs of tool adjustment, install the tool on the lathe spindle.
b. Install and clamp the workpiece to the workpiece fixture of the machine tool, ensuring that the clamping is firm and stable.
6. Run the processing program:
a. On the operation interface of the CNC system, select the relevant commands to run the machining program, and confirm the safety conditions.
b. Start the operation of the processing program, and the machine tool will perform corresponding cutting operations according to the preset trajectory and tool path.
7. Monitoring and adjustment process:
a. During the processing, observe the cutting conditions, tool wear, etc. in time, and make appropriate adjustments and replacements as needed.
b. Monitor the running status of the machine tool to ensure the processing quality and safety of the workpiece.
8. Complete processing:
a. After the processing program is completed, stop the processing operation of the machine tool, and carry out related cleaning and finishing work.
b. Inspect the dimensions and surface quality of machined parts to ensure compliance with requirements.

It should be emphasized that the specific operation steps may vary with different double-column CNC lathes and CNC systems. Before operation, read the machine operation manual carefully and operate according to the actual situation. In addition, for the sake of safety, the operator should abide by the corresponding safety regulations and operating procedures.