The invention relates to the field of food safety detection, and provides a detection method for simultaneous determination of residual quantity of five fresh fruit preservatives including methyl-p-hydroxybenzoate, ethyl p-hydroxybenzoate, 2,4-dichlorphenoxyacetic acid, ethyl naphthol and 4-phenyl phenol. The detection method for simultaneous determination of the residual quantity of the five fresh fruit preservatives comprises the following steps: sample extraction, concentration, purification and liquid chromatography-mass spectrography determination. The method is simple and easy to operate in pretreatment, short in analysis time, wide in linearity range, high in sensitivity and accurate in detection result; and the detection limit is lower than 1.0 mu g/kg, and qualitative and quantitative detection requirements of the preservatives can be met.