The invention relates to auxiliary equipment for concrete detection, in particular to an ultrasonic detection aid for a concrete pier. The aid comprises a bushing with a bolt which is closely attached to a pier; 90 DEG bending pipes which are sleeved at both ends of the bushing with the bolt, as well as lining airbags and acoustic pipes which are arranged at vertical sections of the 90 DEG bending pipes and closely attached to the pier, wherein the 90 DEG bending pipe and the bushing with the bolt are in telescopic connection; the lining airbags are connected with airbag gas inflation pipes for inflating; and the acoustic pipes are suspended in semi-circle pipes of the lining airbags through key slot suspension riveting heads of horizontal sections of the 90 DEG bending pipes. The aid cangradually upward detect along with construction progress, can also be applied according to the comprehensive evaluation of detected data of the top part and two end parts or the combination with the prior method after the completion, has the advantages of convenient application, low detection cost and random sampling of the selection of detection surfaces, cannot cause local failure to concrete, and truly realize non-constructive detection.