Drug synthesis device

The utility model discloses a medicine synthesis device which comprises a synthesis reaction kettle body, a filter assembly comprises a lower exhaust pipe, a lower purification filter screen, an upper exhaust pipe and an upper purification filter screen, a sealing assembly comprises an outer sealing sleeve, an elastic pad, an elastic bulge, a clamping groove, a sealing pad and a sealing groove, and an air outlet assembly is arranged on the surface of the filter assembly. By arranging the sealing assembly, when the lower purification filter screen and the upper purification filter screen need to be detached and cleaned, the exhaust pipe is taken down from the surface of the exhaust fan, the upper exhaust pipe is pulled to the upper end, the elastic protrusions are made to be separated from the clamping grooves, and then the lower exhaust pipe and the upper exhaust pipe can be separated; during mounting, the upper exhaust pipe is pressed towards the surface of the lower exhaust pipe, so that the elastic protrus