Paraxylene disproportionated product fractionation system and processing method thereof

The invention provides a paraxylene disproportionated product fractionation system and a processing method thereof. The method is mainly as follows: after exchanging heat with disproportionated stripping tower bottom liquid, disproportionated stripping tower feed coming from a disproportionation reaction separation unit enters a stripping tower; stripping tower top oil gas exchanges heat with C6-C7 arene extracted from arene, the disproportionated stripping tower bottom liquid is then mixed with the heat-exchanged C6-C7 arene after exchanging heat with the feed, and then enters a benzene tower after heat exchange and carclazyte refining, benzene tower bottom liquid enters a toluene tower after exchanging heat with toluene tower top oil gas, the toluene tower top oil gas is used as a benzene tower reboiler heat source for heating carclazyte tower feed and toluene tower feed, and in addition, the rest part of the toluene tower top oil gas is used for producing steam. The paraxylene disproportionated product fra