Abstract: Aiming at the problem that traditional gas pressure monitor couldn’t record gas pressure(exactly) and real-timely,the paper designed a coal-seam gas pressure monitor based on ATmega64L with high performance and low-power.It gave software and hardware structure of the gas pressure monitor,and (introduced) circuit design of power supply,gas pressure measuring and data storage,design of power saving and implementation of pressure measuring module.The monitor had small size,light weight and simple operation and could realize gas pressure monitoring on line.Meanwhile,circuit of the monitor was low-power and intrinsic safety so that it could work reliably for long time without replacing battery.