The invention provides a method for detecting quizalofop-p-ethyl and metabolite residues of quizalofop-p-ethyl in a complex matrix. The method is a matrix solid-phase dispersion extraction method and comprises steps as follows: (1), extraction of residues in a sample; (2), purification: an extraction solution obtained in the step (1) is weighed and taken, a purifying agent is added to the extraction solution, and a mixed solution is subjected to matrix solid-phase dispersion extraction; (3), preparation of a standard solution; (4), detection with HPLC-MS/MS (high performance liquid chromatography-tandem mass spectrometry); (5), establishment of a standard curve; (6), result analysis. The detection method can determine quizalofop-p-ethyl and the metabolite residues of quizalofop-p-ethyl rapidly, sensitively and accurately, and a new detection technology is provided for detection of herbicide quizalofop-p-ethyl and the metabolite residues of quizalofop-p-ethyl.