Abstract: Measurements of acoustic transmission loss in convergence zone are an important part of underwater acoustic survey. Among various parameters of the explosive sound source, the release interval has a direct effect on the characterization of the acoustic transmission loss structure in convergence zone. Based on Argo data, RAM acoustic propagation model and experimental data, the structures of acoustic transmission loss in convergence zone for different release intervals are compared. The results indicate that under the conditions of different sound source depths and frequencies, the fine characteristics of the acoustic field structure in convergence zone can be well described at the release interval of 0.5 km, the requirement for fine measurement of the convergence zone structure can be met at the release interval of 1 km, and a release interval of 2 km can be used to measure the general structure of the convergence zone, but the peak structure of the convergence region may be missed or the convergence region gain may not be accurate. In consideration of these results and the fact that 0.5 km release interval is impracticable for the whole survey line under the existing conditions, it is suggested that fine measurement of convergence zone, 0.5-km release interval in the convergence zone and 1-km release interval intervals in the shadow zone should be used in the sea area where the range of convergence zone can be known in advance, 1-km release interval can be used on the whole survey line in the unknown sea area; for a survey which aims at getting the general structure of acoustic transmission loss in convergence zone, 2-km release distance interval can be adopted.