The invention relates to a maintenance-free type moisture absorber without an oil cup. The maintenance-free type moisture absorber comprises two moisture absorption tanks and a general three-way tube, wherein moisture absorption tubes are arranged in the moisture absorption tanks; the upper end of the total three-way tube is connected with an electrical equipment pipeline; openings at the two ends of the total three-way tube are connected with a first solenoid valve pipeline and a fourth solenoid valve pipeline after passing through a second solenoid valve and a third solenoid valve as well as branch three-way tubes on the corresponding sides, respectively; the other openings of the branch three-way tubes are connected with moisture absorption tube pipelines of the corresponding moisture absorption tanks; a plurality of air guide holes are formed in the upper part of an air guide section; the lower ends of the moisture absorption tubes are connected with a moisture absorption tube sealing plate by a first spring return assembly; a gas exhaust hole is formed at one side of the bottom of each of the moisture absorption tanks, and a gas inlet is formed at the other side of the bottom of each of the moisture absorption tanks, a gas exhaust opening sealing plate is connected on the gas exhaust opening, and a gas inlet sealing plate is connected on the gas inlet. The maintenance-free type moisture absorber without the oil cup disclosed by the invention is simple in structure, convenient to manufacture, low in cost, capable of effectively preventing moisture of outside air from entering a transformer so as to guarantee the equipment safety, and further guarantee that the transformer continuously operates, and thus the operation cost is reduced.