The invention discloses a method for synchronously detecting seventeen antipsychotics in a blood sample. The method comprises the steps that the sample is extracted with a mixed solution of methanol and acetonitrile to obtain supernate, and after a solvent is removed from the supernate, the supernate is dissolved in a methanol aqueous solution and filtered to obtain a specimen; a high performanceliquid chromatography tandem mass spectrometry method is adopted to detect the specimen; the sample is serum or plasma, and the antipsychotics are amisulpride, aripiprazole, dehydro aripiprazole, chlorpromazine, clozapine, desmethylclozapine, fluphenazine, haloperidol, olanzapine, paliperidone, perphenazine, quetiapine, risperidone, 9-hydroxyrisperidone, sulpiride, ziprasidone and thioridazine; inthe high performance liquid chromatography, a mobile phase A is an aqueous solution of formic acid, and a mobile phase B is a methanol solution of the formic acid; and the mass spectrometry adopts amulti-ion reaction monitoring mode of positive ion electrospray ionization.