Most of the existing waste bin products are single-layer structure, the harmful gases and aerosols in the garbage are easily volatilized into the air, resulting in secondary pollution of the surrounding air, and users are easily contacted and infected by germs. In view of this situation a design scheme of a medical waste bin is carried out, combined with the IRIS mechanism in the space taking advantage of the occupancy, the medical waste bin with an internal isolation door that used IRIS mechanism is proposed. And then the motion simulation of the internal mechanism is carried out. The waste bin product adopts double-layer isolation, and the internal isolation door adopts IRIS mechanism, which takes up a small space rate.The waste bin product can effectively prevent the overflow of harmful gases and aerosols by means of the isolation door, thereby reducing the risk that users are infected with germs due to unreasonable design of the waste bin.