A full-automatic detecting system and method for a transformer. The system comprises a material delivery line; a feed device; a detection delivery line; insulating test devices; error detecting devices; a laser marking device; a discharge device; and a detection management system. The insulating test devices, the error detecting devices, and the laser marking device are sequentially arranged beside the detection delivery line. The material delivery line, the detection delivery line, and the devices work in coordination, to realize full-automatic detection of the transformer, avoid manual detection errors and improve the sorting accuracy.