The invention relates to a DC/DC parallel operation output adjusting method and system. Output of a DC/DC parallel system and output of each DC/DC device are monitored; the output of each DC/DC deviceis fed back and adjusted; therefore, the system output and the output of each DC/DC device satisfy the standard; based on the satisfaction of the standard, optimizing feedback adjustment is continued, and finally, the quality of output electricity is effectively improved, the output of each DC/DC device is optimized, and lives of a powered device and each DC/DC device are greatly extended.