The occurrence of accidents during the storage and transportation of dangerous chemical is catastrophic, which brings about a devastating blow to people’s loss of life and property. There are multiple factors causing the accident, and the unsafe behaviour caused by psychological effect of people in the process of storage and transportation is the main cause. Thus, it is necessary to study the mechanism of psychological effect on human unsafe behaviour. To this end, based on the theory of psychological field, this paper identifies the factors of inducing unsafe behaviour under psychological effect, and analyses the interaction between various factors. Then, it combines the coupling theory to conduct vector analysis for the coupling between various factors, so as to reveal the mechanism of psychological effects on the unsafe behaviour during storage and transportation of dangerous chemicals. This has certain guiding significance for reducing the incidence of accidents in storage and transportation of dangerous chemicals.