The application provides a synthesis method of p-
benzoquinone dioxime. The synthesis method comprises the following steps: (1) adding
solid acid into an
ethanol solution of
phenol to obtain a
mixed solution A, then vacuumizing and filling with
inert gas; dissolving
nitrite into
ethanol, uniformly mixing to obtain an
ethanol solution of
nitrite, then vacuumizing and filling with
inert gas; in an
inert gas
atmosphere, adding the ethanol solution of
nitrite into the
mixed solution A dropwise to perform
nitrosation reaction, to obtain a reaction liquid B; in the
inert gas atmosphere, adding an ethanol solution of
hydroxylamine into the obtained reaction liquid B to perform oximation reaction; after the reaction is completed, filtering the obtained reaction liquid C, performing reduced pressure
distillation on the obtained filtrate, and performing washing, filtering and
drying on the obtained residual liquid of the reduced pressure
distillation, to obtain p-
benzoquinone dioxime. The method provided by the application reduces the occurrence of side reactions, improves the conversion rate of the reaction, and improves the yield and purity of p-
benzoquinone dioxime.