[Objectives]  To evaluate the effectiveness, environmental benefit and cost-effectiveness, of using the parasitoid wasp, Trichogramma dendrolimi Matsumura, as a biological control to protect sorghum, an important crop used for food, animal feed, sugar production and wine-making in China. [Methods]  An experimental trial of the release of T. dendrolimi to control a variety of lepidopteran pests was carried out in the sorghum planting area of Hengshui county, Hebei province over two consecutive years. Biological control by releasing Trichogramma, and chemical control of pests were conducted in sorghum fields in two different villages. The effectiveness of the two different pest-control methods was assessed by comparing the amount of crop damage, the abundance of predatory natural enemies and sorghum grain yield, between these villages. We also conducted a cost-benefit analysis in order to evaluate the overall ecological and economic benefits of releasing Trichogramma compared to using chemical control. [Results]  Fields in which Trichogramma were released had less plant damage, a greater abundance of predatory natural enemies, higher grain yield and greater profit, compared to those that used chemical control. In 2019, fields in which Trichogramma were released had significantly reduced leaf damage, a 3.96 fold greater abundance of predatory natural enemies and a slightly higher grain yield with lower pest control costs than those that used chemical control, resulting in an increase in net differential income of 305.47 yuan/hm². In 2020, fields in which Trichogramma were released had significantly reduced ear damage, a 2.66-fold increase in the abundance of predatory natural enemies and 1 392.5 kg/hm² higher grain yield than those that used chemical control, albeit with slightly higher cost, resulting in an increase in net differential income of 3 644.05 yuan/hm² (19.90%). [Conclusion]  Compared to chemical control, the release of T. dendrolimi not only significantly reduced crop damage, but sustained the biodiversity and abundance of the natural enemies of crop pests, thereby significantly increasing production and income. As a result, releasing Trichogramma to control sorghum pests is a practical and efficient biological control solution for sustainable pest control in sorghum plantations.