Pipeline defect internal inspection device

The invention provides a pipeline defect internal detection device. The pipeline defect internal detection device comprises an ultrasonic detection device and an intelligent terminal, the ultrasonic detection device comprises a waterproof protective shell and an ultrasonic transceiving transducer arranged in the waterproof protective shell; the ultrasonic transceiving transducer comprises a transducer assembly, a motor for driving the transducer assembly to rotate and a sensor for detecting the posture of the transducer assembly; the waterproof protective shell is made of an acoustic transmission material; the intelligent terminal is connected with the ultrasonic detection device through a data cable so as to receive an echo signal and attitude information transmitted by the ultrasonic detection device; in the working process, the transducer assembly emits ultrasonic signals to the periphery of the pipeline and sends ultrasonic echo signals reflected by the inner wall of the pipeline to the intelligent termin