Safety assessment about source of hazardous chemicals is an important element in the safety production management. Its model has been introduced, moreover, a series of factors which can affect inherent hazard and real danger have been analyzed in this essay. A mathematical model can be established and put into practice. Through specific analysis of the realities of the Source of Hazardous chemical, it is easy to find that real danger has to do with many factors: Technology level, equipment level, the degree of the quality of personnel. These factors can offset and control the risk, therefore the real risk has been greatly reduced compared with the inherent risk.