[Objectives]  To develop an improved method of extracting host plant DNA from Apolygus lucorum (Hemiptera: Miridae) in order to facilitate the use of DNA-based technology to explore patterns of host plant utilization by this mirid bug in the field. [Methods]  We used a CTAB-based method and two commercial DNA extraction kits to extract cotton DNA from the gut of A. lucorum and compared the detection rates of cotton DNA among these three extraction methods. Secondly, we compared the effect of washing A. lucorum adults in a 1%-1.5% sodium hypochlorite solution for different periods of time on removing plant DNA contamination from the body surface, and on the detection rates of cotton plant DNA within the body. [Results]  The CTAB-based DNA extraction protocol achieved significantly higher detection rates of cotton plant DNA than the two commercial kits. Washing in 1%-1.5% sodium hypochlorite for 5s successfully removed plant DNA contamination from the body surface of A. lucorum but did not destroy internal cotton plant DNA. The detection rate of cotton plant DNA did, however, decrease significantly after washing for 30 s. [Conclusion]  This study established a feasible method to remove external plant DNA contamination from the body surface of A. lucorum and confirmed that DNA can be extracted from the entire body of adult A. lucorum instead of just the gut. It provides an important foundation for the use of DNA-based technology to track the feeding behavior of A. lucorum.