Abstract: ‍ ‍When using the bistatic sonar system to locate targets， different configuration patterns and structures can cause significant differences in positioning performance， so it is crucial to optimize the design of the configuration structure of the bistatic sonar system. To solve this problem， the article derives the error estimation of the Cramér-Rao bound （CRB） for bistatic sonar based on active Time-only Localization （TOL） method， and researches the optimal spatial configuration design problem of bistatic sonar systems with the highest positioning accuracy as the optimization objective. Among them， it is standardized that the applicable scenario where the system timing error obeying the zero-mean Gaussian white noise is the cooperative location scenario. For the non-cooperative location scenario， the mathematical expression of the system timing error varying with the target distance is derived. Therefore， correcting the Cramér-Rao lower bound （CRLB） of the bistatic sonar. Besides， the focus was on exploring the impact of factors such as system timing errors and sound velocity fluctuations on target positioning accuracy. Finally， simulation results show that optimal configuration of uncorrected bistatic sonar is at the separation angle of value in $\mathrm{101.5}°$. But the corrected bistatic optimal configuration is related to system configuration. With the increase of the system configuration ratio， the bistatic optimal separation angle will get closer and closer to $\mathrm{90}°$. And this research can provide array reference for optimal configuration of the bistatic/multistatic sonar system.