The invention relates to the field of production equipment, in particular to an assembling mechanism of a production device of a harmonica. The assembling mechanism comprises a supporting assembly, ajacking mechanism and a screw assembling assembly. The jacking mechanism comprises a first jacking assembly and a second jacking assembly. The screw assembling assembly comprises a first assembling assembly and a second assembling assembly. The supporting assembly comprises a supporting table and a tightening assembly. The tightening assembly comprises a horizontally-arranged connecting plate andtightening column heads distributed at the bottom of the connecting plate in a matrix manner. The outer side of each tightening column head is sleeved with an airbag. All the tightening column heads are provided with air conveying holes communicating with the airbags. The connecting plate is provided with a cavity communicating with all the air conveying holes. The connecting plate is provided with an air inlet hole communicating with the cavity. A first screw locking machine and a second screw locking machine of the assembling mechanism can suck microscrews, then the microscrews are preciselymounted at corresponding positions, and the production efficiency is improved.