The intelligent technology represented by the big data and artificial intelligence is dominating the comprehensive and far-reaching transformations in the criminal justice field in our country. Compared with the active and comprehensive self-renewal conducted by the Courts and Procuratorates, although the intelligent technologies have been applied to a certain extent in the field of defense, the limited integration throughout the defense process is still in the early stages of development. Actually, the current defense can be transformed into the sapiential defense driven by big data technology, which includes: changing the way lawyers work, from the office automation to the intelligent service; assisting lawyers to make defense decisions, in the process of reviewing file, examining evidence, recommending similar case, mining judicial disciplines, and so on; developing the business areas of criminal risk prevention and control, and reshaping the business-oriented positioning. However, in the process of transformation, we should pay attention to the following aspects: broadening the data sources; learning the experience from the Courts and Procuratorates based on specific conditions; and adhering to the dominant position of the law in the fusion of law and technologies.