The utility model discloses an ultra-large type wafer K1 probe, and relates to the technical field of devices used for detecting or analyzing materials through ultrasonic waves, acoustic waves or infrasonic waves. The ultra-large type wafer K1 probe comprises a cable joint, a housing, a lead, a sound absorption material, a sound transmission tapered wedge, a damping block and a self-transmit self-received piezoelectric chip wafer; the cable joint is positioned on the housing; the sound transmission tapered wedge is fixed on the lower bottom surface in the housing; the housing is full of the sound absorbing material; the self-transmit self-received piezoelectric chip wafer is clung onto the a tapered surface of the sound transmission tapered wedge and is connected with the cable joint through the lead; the damping block is fixed on the self-transmit self-received piezoelectric chip wafer. The probe has the characteristics of being large in detection coverage area, high in efficiency, and easy to detect the longitudinal linear defect of a base material of a steel pipe.