Abstract: The forecast of the technology progress probability through BNM, its implication of the technical and economic indicates the character of the technology progress, corresponds to the process of the technology innovation for the firms. At first, the thesis analyses the sets of the technology progress in each stage and their relations, inferences and judges the relevance of the pre-stage of the technology progress and the current stage, the current stage of the technology progress and next stage, the condition of the rational forecast of the technology progress is more enough. According the research, the firms select the technical diffusion, rational forecast of technology progress is feasible, is a proceed in an orderly way and step by step, from un-rational forecast to bounded rational, then to whole rational forecast. The sets of the probability of the technology progress have the character of RIP, the probability of each stage of the technology progress has relation only with the pre-stage, with no relation of the next stage. The intersection of the probability sets among two stages of the technology progress is larger, their relevance is more closer each other, the probability to advance higher stage is higher. The difference of the rational forecast of the technology progress is the necessary condition for optimization selection of the technology progress path, the result of rational forecast is more correct with shorter path of the technology progress. Empirical analysis confirms the nodes of the technology progress stage, draws DAG with patent citation, technical intense, general index, relation of the science and technical, then carries the analysis of the cause and diagnostic reasoning, and verifying the conclusion.