The invention discloses a production method for
dimethyl ether, which comprises the following steps: 1) feeding a
raw material methanol into a
methanol vapor-liquid separator, vaporizing the
methanol into methanol vapor by heating, further heating the methanol vapor to 320-325 DEG C by a
heat exchanger, feeding the methanol vapor into a
dimethyl ether reactor, and in the presence of a catalyst, carrying out a methanol
dehydration reaction at a temperature of 380-395 DEG C, so that crude methyl
ether gas is generated; and 2) after the crude methyl
ether gas obtained in the step 1) is preheated to 119-121 DEG C by a crude methyl
ether preheater, feeding the crude methyl ether gas into a
distillation system, passing the crude methyl ether gas through a
reboiler of the
distillation system so as to heat the crude methyl ether gas by using low-pressure vapor, so that a fine
dimethyl ether product is produced by distilling. According to the production method, a situation that a dimethyl ether
system obtains enough heat, so that the production is running stably is ensured; the stepped utilization of vapor is realized, and the heat of vapor is maximumly utilized, and therefore, a problem that when an original dimethyl ether system uses medium-pressure vapor, a large amount of low-pressure vapor is emptied, so that the
wasting of resources is caused, is solved; and the method saves resources, reduces the production cost, and has good
economic benefits.