Halogenation, oxidation, diazotization, nitration and hydrogenation are important reactions in fine chemical production, which are generally carried out in batch reactors currently, leading to potential safety hazards and low efficiency. The development of microchannel reactor technology provides an effective platform to solve the above problems. Therefore, the investigation on synthetic processes with safety and efficiency in microchannel reactors has become one of the hotspots in the area of fine chemicals. Herein, the research progresses in the synthetic processes of fine chemicals involving hazardous reactions in microchannel reactors in recent years are summarized, from which it can be concluded that fine chemical production could be performed in more safe and efficient protocols in the future. Besides, the current deficiencies of microchannel reactors and the research directions were pointed out.