Abstract: First, the results of construction workers' hazard cognition of different accidents are obtained by using the psychometric paradigm. Then the differences between construction workers in hazard cognition are explored by making a classification and a comparison. At last, in order to improve construction workers' hazard cognition, some deeper problems are analyzed based on the cognitive psychology, which include characteristics of hazard cognition's result, change rules of hazard sensitivity, causes of hazard cognition bias. The results show that the results of hazard cognition are related to the degree of stimulation of hazard characteristics to workers and the sensitivity of workers to the stimulation closely. Under the same conditions, there is a large difference between workers in the perception of the hazards having low potential for damaging, a high occurrence frequency, visual indication, and good controllability, and the hazards are liable to be underestimated easily, that there is a danger of adaptation among workers , resulting in a decrease in hazard sensitivity and a lack of hazard perception, and that the main reasons of the workers' hazard cognition bias are the decrease of hazard sensitivity, the excessive subjectivity of hazard cognition and the overvaluation of hazard response ability.

Key words: construction safety, construction worker, hazard cognition, behavior based safety, difference analysis