GT-20 rail flaw detector is the third generation of full digital and portable hand push rail for railway Ultrasonic flaw detection equipment. The equipment fully meets the requirements of TB / T 2340-2012 rail ultrasonic flaw detector of the Ministry of railways, is suitable for the flaw detection of 43kg / M ~ 75kg / m rail, can efficiently detect various defects of rail head, waist and bottom, and is suitable for various rail detection applications such as ordinary railway, high-speed railway and subway. The instrument adopts ultrasonic host + operation terminal mode and connects with wireless WIFI. It improves the user experience and expands the Internet plus function of the instrument. It can realize man-machine detection and separation, data online, offline real-time storage, GPS positioning, data cloud storage and other functions. And can customize their own ultrasonic operation terminal according to their own needs.