Urban sewage, aquaculture wastewater, and medical wastewater are significant reservoirs and transmission sources of . Rapid detection of is crucial for effectively reducing the risk of disease transmission and safeguarding public health. Differentiating viable from inactivated cells presents significant challenges, affecting the accurate assessment of pathogen risks. Moreover, current detection methods face several limitations, including lengthy detection periods, high costs, and limited applicability, underscoring the need for rapid, sensitive, and visual detection diagnostic approaches. In this study, we combined propidium monoazide (PMA) with recombinase polymerase amplification (RPA) and clustered regularly spaced short palindromic repeats (CRISPR)/Cas12a systems to develop a rapid detection system for viable targeting the Y gene. DNA of viable was amplified and visually detected within 60 min and dead cells were effectively excluded. We assessed the specificity and sensitivity of the PMA-RPA-CRISPR/Cas12a assay. The results showed that the assay had a high level of specificity, with no reactions observed with other pathogens. The application of PMA has no effect on the sensitivity of RPA-CRISPR/Cas12a technology and the visibility of the fluorescence reporting system. We successfully detected viable in wastewater with a minimum detection limit of 10 CFU/mL. In summary, the PMA-RPA-CRISPR/Cas12a system developed in this study allows for the rapid and visual detection of viable in wastewater at concentrations as low as 10 CFU/mL. By integrating PMA with the RPA-CRISPR/Cas12a technology, this system offers valuable technical support for the efficient, sensitive, and clear detection of viable in wastewater.