[Objectives]  To verify the interaction between cryptochrome (Cry) and iron-sulfur cluster assembly 1 (IscA1) protein in eukaryotes, and to study the role of these two proteins in the development and reproduction of brown planthopper, Nilaparvata lugens, so as to provide a basis for investigating the synergy between these proteins in magnetoreception and the physiological regulation of the magnetic field in insects. [Methods]  The interaction between N. lugens Cry1/Cry 2 and IscA1 was verified using yeast, two hybrid technology. The RNAi (RNA interference) silencing model of Cry1/IscA1 gene was established in 3^rd instar nymphs and 1-day-old adults and the silencing efficiency of these two genes detected by RT-qPCR. The duration of the nymph period and the oviposition rate of silenced individuals were measured. [Results]  There is an interaction between Cry1 and IscA1 in N. lugens but not between Cry2 and IscA1. The RNAi silencing model of the Cry1/ IscA1 gene was successfully established in 3^rd instar nymphs and 1-day-old adults; the silencing efficiency of these two genes was > 70% on the 2nd, 4th and 6th day after dsRNA injection. There was no change in the duration of the nymph period after Cry1/IscA1 gene silencing but oviposition was significantly inhibited. [Conclusion]  Cry1 interacts with IscA1 in N. lugens and plays an important role in the reproduction of this species.