Abstract: Aiming at the thick walled asymmetry weld, this paper analyzed the TOFD signal propagation regularities of thick walled asymmetry weld through modeling and simulation. Combination of different angle wedges and probe revisions was adopted and different probes were used to study the signal propagation regularities in asymmetry weld. The feasibility of using TOFD testing method for asymmetry weld in practical testing application was verified, and it provided guidance in the practical detection.