Automation and industrialization is the trend of pig industry. Real time detection of parturition is one of the key technologies of sow automation farming. Video image features of sows parturition were analyzed to detect sows parturition by recognizing piglet. The moving objects were detected based on the improved single Gaussian model. Disturbance of sow moving was removed by the arithmetic of matching semi circle. According to the color and size characteristics of newborn piglets, targets were recognized. Test results showed that the sow object could be recognized effectively by the proposed approach. The moving objects detection method based on the improved single Gaussian model detected the slow moving piglet completely after eliminate interference.