The invention relates to a sitting posture correcting device and method. The sitting posture correcting device includes a sitting posture correcting costume, a calibration device, a distance measuring device, a regulator and a central processor, wherein the central processor is connected with the calibration device, a wireless transmitting-receiving device and the distance measuring device. With the sitting posture correcting device and method adopted, real-time monitoring and fast analysis can be achieved, and with an alarm device used in cooperation, sitting posture correction can be realized.