The present invention provides an A type pulse reflection ultrasonic wave probe fixation apparatus, which is characterized by comprising a surface fixation unit and a probe fixation unit, wherein the surface fixation unit comprises a bracket and at least two magnets, both ends of the bracket are respectively provided with at least one magnet so as to fix the bracket on the pipe wall, and the probe fixation unit is arranged on the bracket and is used for providing pressing force on an A type pulse reflection ultrasonic wave probe placed on the pipe wall so as to fix the A type pulse reflection ultrasonic wave probe on the pipe wall. With the A type pulse reflection ultrasonic wave probe fixation apparatus of the present invention, the difficult problem that the traditional measurement method cannot achieve the accurate defect measurement when the defect is measured during the thermal power plant boiler pipeline detection process is solved, and the problems of excessive grinding, grinding out of defects, and the like during the defect eliminating process are avoided.