Diesel engine urea solution adding device

The utility model relates to a diesel engine urea solution adding device, which belongs to the technical field of engine exhaust treatment. The device comprises a urea box, N pressure cavities, a switch valve, an air lead-in and lead-out pipe, a three-way valve, a urea solution lead-out pipe and a control unit, wherein the pressure cavities are connected with the urea box, the switch valve realizes the control, the air lead-in and lead-out pipe is positioned at the top part of the pressure cavites, the three-way valve is positioned at the top part of the air lead-in and lead-out pipe, the urea solution lead-out pipe is positioned at the bottom part of the pressure cavities, the other end of the lead-out pipe is sequentially connected in series with a urea solution flow rate controller and a urea solution spray nozzle, and the control unit is connected with the three-way valve, the switch valve and the urea solution flow rate controller. The utility model provides a pump-free urea solution adding device with the advantages of low energy source consumption, simple structural form, low device cost, reliable operation and good atomization effect.