The rapier loom HMI system is a kind of device which is used to send command to the loom, monitor the running status and store the loom data. Its main functions are providing a friendly human machine interface, setting the loom parameter, communicating in real time and storing the machine data necessary. This paper introduces a rapier loom HMI implementation scheme. It runs on the MCU of STM32F429IGT6. In the aspect of software design, this paper comes up with a cross-platform GUI which is easy developed and has good portability. The experimental results show that the HMI system can meet the industrial requirement on indicating the rapier loom and get feedback of the machine.