In ultra precision machining processes, an effective monitoring system can maintain machine tools in the best condition and delay the occurrence of tool wear and improve the quality of workpiece. In this paper, a distributed system is developed for monitoring of multi-machine tool based on wireless sensor network. Firstly, the sensor in the machine tool is responsible for the information collection and data processing. Secondly, the wireless network is used to transmit the data or receive the commands from the computer of control center. Finally, the computer will monitor the overall system and generate the alarm signals or the commands when the change of environment information occurs. The experimental results have shown the effectiveness of the proposed distributed system.