Abstract: In view of problems of bad effect of closed-loop control and poor communication function existed in traditional control instruments of electronic belt scale which uses single-chip microcomputer to realize aggregation operation and control, a design scheme of control instrument of electronic belt scale based on ARM was proposed, and design of hardware and software of the instrument were introduced in details. The instrument is composed of data collector and display controller based on ARM. The instrument uses separate type of structure, namely data collector is installed at site, display controller is installed at monitoring room, and the both communicate through RS485 interface. The experiment result showed that the measuring precision of the instrument is superior to 0.2% and the instrument has reasonable design.