The present application provides a pipeline structural fault diagnosis apparatus and a diagnosis method. The pipeline structural fault diagnosis apparatus includes a signal generating apparatus configured to generate an acoustic wave signal by knocking a pipeline; a signal collecting apparatus configured to collect the acoustic wave signal; a signal storage apparatus configured to store the acoustic wave signal for a signal processing and analyzing apparatus to analyze and determine a fault type, a fault degree, and a fault position. The acoustic wave signal after being generated by the signal generating apparatus is collected by the signal collecting apparatus and stored in the signal storage apparatus. The signal processing and analyzing apparatus extracts the acoustic wave signal in the signal storage apparatus, and performs processing and analysis to determine the fault type, the fault degree, and the fault position of the pipeline structure.