The invention relates to a polyformaldehyde
dimethyl ether synthesis method which mainly solves the problems of difficult catalyst separation, low
raw material conversion rate and poor product selectivity in the prior art. The technical scheme of the polyformaldehyde
dimethyl ether synthesis method comprises the following steps: by taking
methanol, methylal and polyformaldehyde as raw materials, under the conditions that the
reaction temperature is 70-200 DEG C and the reaction pressure is 0.2-6 MPa, enabling the raw materials to be in contact with a catalyst, and reacting to generate polyformaldehyde
dimethyl ether, wherein the weight ratio of the
methanol, the methylal and the polyformaldehyde is (0-10):(0-10):1, and the amounts of the
methanol and the methylal can not be 0 at the same time; the amount of the catalyst accounts for 0.1-5.0% of the weight of the raw materials; and the used catalyst comprises the following components in parts by weight: a) 30-80 parts of carrier, which is at least one selected from SBA-15, MCM-41 or MCM-22
molecular sieve, and b) 20-70 parts of
solid super-strong acid carried thereon, which is at least one selected from SO4<2-> / ZrO2, SO4<2-> / Fe2O3, Cl<-> / TiO2 or Cl<-> / Fe2O3. Thus, the problems are well solved; and the polyformaldehyde dimethyl
ether synthesis method can be used for industrial production of polyformaldehyde dimethyl
ether.