Abstract: The effective utilization of industrial solid waste is an important issue in many industries to significantly reduce the consumption of cement or lime. However, the application and the methods determining dosage ratio of such materials usually rely on a large number of experiments and experience, lacking guiding principles for reasonably proportioning methods. This study aims at proposing an approach for designing dosage ratio of multi-source curing agents, taking common industrial solid wastes of steel slag, fly ash, phosphogypsum and lime as an example. The unconfined compressive strength tests are performed on the line-based multi-source stabilized soil identifying the influence of three chemical moduli on strength behavior. The scanning electron microscopy tests and the neural network method are also carried out for understanding the changing law in micro-behavior with different three chemical moduli. The research results show that the stabilized soil group proportioned according to the three chemical moduli exhibit higher strength than the other groups. It is also found that the calcium sulfur ratio has a significant impact on the strength of the solidified samples. Consequently, the optimization method is proposed for determining the proportions of the multi-source curing agents based on the three chemical moduli combiend with the calcium-to-sulfur ratio. The mechanism responsible for the influence of oxide and rod-like Aft (ettringite) gel microstructure on the strength of the solidified samples is revealed by linking the macro-and micro-behaviour. The changing patterns of microstructure induced by the change in three chemical moduli and the calcium sulfur ratio are clarified. The correlations between the strength behavior and the overall area, number and size of pores are established.