An early warning system was established to predict and assess the “Not In My Back Yard” of heavy pollution projects.•
The early warning indicator system for the “Not In My Back Yard” was constructed based on public perception.•
The early warning model was developed based on the ordered weighted averaging operator and cloud model.•
The implementation framework of the early warning system was established.•
An empirical study was demonstrated to test the feasibility and rationality of the early warning system.
Due to the negative impact of Heavy Pollution Projects (HPPs) on the surrounding environment and the general public’s daily life, HPPs are often resisted by the public during the site selection process, resulting in “Not in My Back Yard (NIMBY)” events, which hinder the implementation of the project. Demonstrating an early warning system is important to determine the NIMBY likeliness of HPPs. However, the existing literature related to the NIMBY assessment has deficiencies in terms of the assessment subject, method, and procedure. The aim of the study was to establish an early warning system to determine NIMBY level of HPPs in China. The early warning system was constructed based on the ordered weighted averaging operator and cloud model from the perspective of public perception. The results showed that the NIMBY level of the case project was “Center”, and the indicators with “High” level included the public security influence, the impact of production safety accidents, the impact of wastewater pollution, and the impact of toxic gas pollution. Finally, by analyzing the NIMBY issues for the project, we propose suggestions for the prevention and treatment of social security issues, production safety accidents, and wastewater and toxic gas pollution. To reduce the NIMBY level and ensure the smooth implementation of the project, the environmental protection department of the government should strengthen its environmental protection supervision, and the enterprise should strengthen the social safety management of workers, establish a perfect production management system, and upgrade and improve the treatment facilities of wastewater and toxic gas.