The present disclosure provides a nozzle cleaning device, a doctor blade replacing apparatus and a doctor blade replacing method. The doctor blade replacing apparatus includes a first doctor blade box, a second doctor blade box, a transferring assembly and a clamping and conveying mechanism. The transferring assembly includes a first tray which is disposed between the first doctor blade box and the second doctor blade box and a pushing assembly which is configured to push the first doctor blade in the first doctor blade box to the first tray and push the second doctor blade on the first tray into the second doctor blade box. The clamping and conveying mechanism is disposed between the first tray and the nozzle cleaning device for clamping and conveying the first doctor blade and the second doctor blade between the first tray and the nozzle cleaning device.