We report the first record of the webspinner family Ptilocerembiidae Miller & Edgerly, 2012, from China, represented by a new species, Ptilocerembia qiului sp. nov. , discovered in Yunnan Province. Detailed morphological examination, particularly the comparative analysis of male terminalia, clearly distinguishes this species from its congeners. The complete mitochondrial genome of P. qiului sp. nov. (15,443 bp) was sequenced, exhibiting the canonical insect gene order with strong A+T bias but showing the absence of two tRNAs (trnV and trnS2). Notably, we detected novel tandem repeats between trnI and trnQ, a feature not reported from other sequenced embiopteran mitogenomes. All protein-coding genes evolve under purifying selection, with COX1 showing the highest conservation. DNA barcoding (COX1) and phylogenetic analyses further support species delimitation in Ptilocerembia , with interspecific divergences between the new species and other Ptilocerembia (12.6–17.6%) far exceeding frequently used intraspecific thresholds (~2%). The discovery extends the known distribution range of Ptilocerembiidae northeastward to southwestern China. Our integrative morphological and molecular framework highlights the previously underestimated species richness in Ptilocerembia and provides the first mitogenomic insights into Ptilocerembiidae.