The utility model relates to an underground oiling machine, which comprises a pneumatic pump and a pressure regulating filter, wherein the pneumatic pump and the pressure regulating filter are fixedly arranged in a box body of the oiling machine, an oil sucking opening, an oil outlet and an air inlet are formed in the pneumatic pump, an oiling opening is connected with an oil source, and the pressure regulating filter is connected with the outer part of the air inlet. The underground oiling machine has the advantages that the automatic oiling can be realized, the labor is saved, and in addition, the time is also saved. The motive power source of the underground oiling machine is wide compression gas, the underground oiling machine is applicable to environment of mines with rich wind energy pipelines, and the like, the oil liquid conveying and filling efficiency can be greatly improved, and the labor is greatly reduced.