Abstract: The paper introduced design schemes of software and hardware, debug methods, problems in debug process and optimization methods of a battery-powered early warning circuit for shearer starting. The circuit takes 12 V battery as system power supply, uses MSP430F149 single-chip microcomputer to control process of early warning when shearer body is powered up, and real-timely monitors battery capacity. If battery voltage checked by the single-chip microcomputer is lower than low-voltage threshold value preset in program, the circuit would give out blinking signal, which can remind users to charge the system battery. The whole circuit works in low power dissipation mode when it is idle to prolong service time. After debug and optimization, the circuit's program runs correctly and static power dissipation of the circuit is only 0.2 mA, which meets design requirement of low power dissipation.