Abstract The direct CP asymmetry in the weak decay process of hadrons is commonly attributed to the weak phase of the CKM matrix and the indeterminate strong phase. We propose a method to generate a significant phase difference through the interference between $\rho$ and $\omega$ mesons, taking into account the G-parity allowed decay process of $\omega \rightarrow \pi^{+}\pi^{-}\pi^{0}$ and the G-parity suppressed decay process of $\rho^{0} \rightarrow \pi^{+}\pi^{-}\pi^{0}$ in B meson decays. 
It can lead to a significant CP asymmetry changes in the interference region. 
Besides, we also calculate the integral results of different phase space regions for the four-body decay process. We hope that our work can offer valuable theoretical guidance for future experimental investigations on CP asymmetry in these decays.Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.