The invention discloses a storage battery repair device, which comprises a microcontroller, an alternating current to direct current (AC/DC) conversion circuit, a direct current to direct current (DC/DC) conversion circuit, a charging/discharging control circuit, a load and a discharging circuit, wherein the output of the AC/DC conversion circuit comprises two paths; one path is connected with the DC/DC conversion circuit, and the other path is connected with a charged battery; the output end of the DC/DC conversion circuit is connected with the microcontroller and the charging/discharging control circuit and supplies power to the microcontroller and the charging/discharging control circuit; the control output end of the microcontroller is connected with the control input end of the charging/discharging control circuit; the control output end of the charging/discharging control circuit is connected with the AC/DC conversion circuit and controls the output of one path, which is connected with the charged battery, of the AC/DC conversion circuit; the discharging circuit is connected with the charged battery; the load is connected with the discharging circuit; and the control end of the discharging circuit is connected with the control output end of the charging/discharging control circuit. In the technical scheme, battery repair quality is enhanced greatly and recovery capacity of the battery is increased from 50 percent to be between 60 and 70 percent.