24-hour round-the-clock monitoring of the estrus status of sows, collecting image data of sows and intelligently judging the estrus status of sows. No experience is needed for estrus checking, reducing misjudgment and omission, and reducing labor cost. Reduced contact between humans and pigs, thus minimizing the risk of disease transmission. When the estrus index of sows reaches 90%, it reminds the best time for breeding, increasing the conception rate of sows by 5%-10%.