【Aim】 To investigate the occurrence and invasion source of Phenacoccus solenopsis in Huizhou, an important invasive pest that invaded China in recent years. 【Method】 In this study, we investigated the infestation of P. solenopsis in Huizhou on collected samples using morphological identification, DNA extraction, and PCR amplification to analyze its sequence homology, genetic structure, and phylogenetic relationship with bioinformatics software. 【Result】 There are 43 species of host plants in 15 families in Huizhou, which include potatoes, vegetables, and other economically important crops. Four haplotypes exist in the mitochondrial COⅠgene sequence, which were compared in the GenBank database. The sequence similarity reached 100%, and the genetic distance between populations was 0-0.029. The genetic distance between the Huizhou and American populations was large, whereas the genetic distance between the Huizhou and other populations was small. A phylogenetic tree showed that the Huizhou and Pakistani populations clustered together in one group. Based on the genetic distance and phylogenetic tree data, it was speculated that P. solenopsis in the Huizhou area may have originated from Pakistan. 【Conclusion】 The mitochondrial COⅠ gene could quickly and accurately identify the invasion source and phylogenetic relationship of this insect, providing a scientific basis for monitoring the occurrence and precise control of this insect in potato and vegetable areas in Huizhou.