The development of robust condition monitoring system for a machine tool spindle is an important task because the spindle has a significant effect on the processing quality. This paper presents the architecture of data acquisition system for detecting spindle vibration in turning processes in order to develop an on-line condition monitoring system. In this work, a solar-powered wireless sensor system is installed inside the spindle and is used to monitor the machine tool processing state in real time, thereby improving the processing quality. Accelerometer sensors are employed to estimate tool wear; these sensors monitor the vibration of the spindle. The vibration monitoring data of the high-speed spindle is wirelessly transmitted to an external information device in real time. As an alternative to sensors that employ wired power transmission, a solar energy transmission system has been developed to provide the required electric power to the sensor system. The experimental results show that the proposed system successfully measures the vibration frequency of the rotational machine tool spindle.