The invention provides a full information recording ultrasonic fault detector. A high-speed processor is connected with a programmable logic circuit and outputs results to a high-speed solid state memory. The fault detector disclosed by the invention has a sound pressure attenuation compensation function, and an amplifier can be dynamically adjusted according to a sound pressure attenuation curve of a detected workpiece, so that the equivalent defects on a base line have consistent display amplitude, and echo information in different distances is conveniently observed by a user. The full information recording ultrasonic fault detector is suitable for serving as an ultrasonic fault detector.