[Aim]  To evaluate the benefits of co-planting basil, Ocimum basilicum, to protect maize crops from insect pests. [Methods]  The olfactory behavioral responses of six parasitic wasps; Trichogramma ostriniae, Trichogramma chilonis, Trichogramma dendrolimi, Trichogramma japonicum, Macrocentrus cingulum and Microplitis mediator to Oc. basilicum, were determined. The effect of basil flowers on the longevity, parasitism and fecundity of the above six parasitic wasps and four main lepidopteran pests of maize (Ostrinia furnacalis, Spodoptera exigua, Spodoptera frugiperda and Helicoverpa armigera), was also investigated and the effectiveness of planting basil was also tested in corn fields. [Results]  Oc. basilicum significantly attracted all six parasitic wasp species, and prolonged the adult longevity of all species, except Ma. cingulum. It also enhanced the parasitic ability of the four Trichogramma species, with the parasitism of T. chilonis, T. dendrolimi, T. japonicum, and T. pretiosum increasing significantly by 48.52% (P < 0.001), 71.21% (P = 0.001), 51.53% (P = 0.001), and 70.63% (P < 0.001). Basil had no significant effect on the longevity (female: H. armigera: P = 0.368; Os. furnacalis: P = 0.877; S. exigua: P = 0.588; S. frugiperda: P = 0.069; male: H. armigera: P = 0.253; S. exigua: P = 0.112; S. frugiperda: P = 0.433) or fecundity (H. armigera: P = 0.447; Os. furnacalis: P = 0.447; S. exigua: P = 0.526; S. frugiperda: P = 0.526) of the four lepidopteran maize pests, except for the longevity of Os. furnacalis male (P = 0.002). The results of field experiments indicate that basil significantly increased the numbers of predatory (95.12%) (P < 0.001), and parasitic (77.55%) (P < 0.001), natural enemies of maize pests, reduced the abundance pest species (30.50%) (P < 0.001), and significantly enhanced corn yield (16.58%) (P < 0.001). [Conclusion]  Basil is an effective nectar producing plant that is attractive to the parasitic natural enemies of maize pests, improves ecological pest control in maize crops, and increases maize yield. These results provide a scientific basis for co-planting basil for ecological pest management in maize fields, and new ideas and methods for sustainable agricultural development.