The utility model relates to a portable passive anesthesia machine. The portable passive anesthesia machine comprises a box, a breathing pipeline, an expiration loop and an oxygen pipe and is characterized in that an anesthetic gas concentration adjustment and control device is arranged on the upper portion of the interior of the box, an anesthetic waste gas absorption device is installed at the bottom of the interior of the box and comprises an anesthetic storage tank, a waste gas absorption particle storage tank A and a waste gas absorption particle storage tank B, a waste gas pressure reduction valve A is connected to the bottom of the waste gas absorption particle storage tank A, a main anesthetic exhaust pipe and an auxiliary anesthetic exhaust pipe are connected to the bottom of the anesthetic gas concentration adjustment and control device, one end of the expiration loop extends out of the box, the other end of the expiration loop is communicated with the waste gas absorption particle storage tank B, the oxygen pipe is communicated with the anesthetic gas concentration adjustment and control device, and the breathing pipeline is connected with the auxiliary anesthetic exhaust pipe. The portable passive anesthesia machine has the advantages that the machine is light in weight and wide in application range, no external power supply is needed, and the concentration of volatile anesthetic can be kept constant; water and carbon dioxide in the expired gas of a patient is used for reacting with the anesthetic waste gas absorption device so that heat can be generated to keep the temperature of the anesthetic constant.