According to the demand of mineral production,a material level monitoring system of bunker based on PLC was designed.The components of the system were selected.Heavy-hammer type material level meter was used into the system.The hardware and software of the PLC control system were designed.The overall monitoring system was debugged.The results of actual measurement showed that the monitoring system is easy in installation,is exactitude in measuring range of material level,its deviation range of measuring is within 15%,the system is of strong adaptability.