The cultivation, development and application of industrial hemp have become an important industry of major companies in the world, and play an important role in the structural adjustment of planting industry. In this study, we mixed dried powder from root and flower and seed from industrial hemp at maturation period with black soil (volume 1:3) for pot experiment to analyze the effects of different treatments on root growth of soybean and maize. The results showed that dry powder of industrial hemp root increased the dry weight of soybean root by 1.67 times that of the control. The dry powder of flower and seed increased the dry weight of maize root by 18.0% compared with that of the control. Dry powder of industrial hemp root increased root length, root surface area and root volume of soybean significantly, but decreased the average root diameter; dry powder of root and dry powder of flower and seed significantly increased root length, root surface area, root volume of maize and the number of root tip, but was not conducive to the increase of the average root diameter. In conclusion, the effects of dry powder of industrial hemp from different tissues on monocotyledon and cotyledon are different, and the study could provide theoretical guidance and technical support for the research and development of industrial hemp in agrochemical products.