The neuropeptide F (NPF) signaling, comprising NPF and neuropeptide F receptor (NPFR), role in regulating insect behaviors and physiological processes. We cloned the genes encoding NPF and NPFR from Plutella xylostella, a notorious pest of cruciferous crops. Notably, the NPF gene produced two splicing variants, Px-NPF1 and Px-NPF2, with distinct expression patterns. Conserved C-terminal RPRFamide motif and seven transmembrane α-helics were observed in Px-NPF and in Px-NPFR, respectively. Px-NPF and Px-NPFR are widely expressed across all larval instars and are predominantly localized in the brain and midgut. The transcriptional levels of Px-NPF1 and Px-NPFR increased and reached maximum at 8 h after food deprived. RNA interference targeting Px-NPF and Px-NPFR resulted in smaller body size, delayed larval growth and alterations in energy metabolism. Specific binding assays revealed stronger binding affinity of Px-NPF1 with Px-NPFR than Px-NPF2. Three-dimensional models of the Px-NPF-NPFR complexes via AlphaFold 3 highlighted the critical roles of two highly conserved residues across insects, Tyr46 and His196, in interaction. Our findings underscore the potential of targeting NPF-NPFR signaling for P. xylostella controlling and contributing to developing novel pest management strategies.