The invention relates to the field of research of nano small particles, in particular to equipment for sealing an isolated ultrafine cluster and a sealing method. The equipment comprises a first processing chamber and a second processing chamber which are divided through an isolation valve, wherein the first processing chamber is used for depositing the ultrafine cluster, CO2 gas is led into the second processing chamber, a transmission bar is arranged on the second processing chamber, and the transmission bar is led into the second processing chamber and can be communicated to the isolation valve to be lead into the first processing chamber. By means of the equipment for sealing the isolated ultrafine cluster and the sealing method, contact is not needed, and maintenance of cleanliness is achieved. Since dry ice is very easy to gasify, particles seem to be in a suspension state when falling on the dry ice.