Recycling treatment method for separating byproduct rich meta-position from mixed dichlorobenzene

The invention relates to a recycling treatment method for separating a byproduct rich meta-position from mixed dichlorobenzene. The method comprises the following steps: performing acylation reaction for the mixed dichlorobenzene comprising m-dichlorobenzene and acetic anhydride in the presence of anhydrous aluminum chloride, and then hydrolyzing, washing, distilling and crystallizing to obtain 2,4-dichloroacetophenone and little dichlorobenzene; performing catalytic orientation isomerization for the little dichlorobenzene by utilizing a high-efficiency HZSM-5 molecular sieve, enabling p/o-dichlorobenzene to be transpositioned to m-dichlorobenzene, wherein the obtained m-dichlorobenzene can be used for producing 2,4-dichloroacetophenone. The recycling treatment method has the advantages that since the price of the m-dichlorobenzene is high, the m-dichlorobenzene in the mixed dichlorobenzene is sufficiently utilized to be treated at the process route, the raw material utilization rate can be effectively increa