The invention relates to the technical field of environmental protection, in particular to an efficient and low power consumption ballast water treatment device. The device contains a sea chest (101), a ballast pump (102), a salinity sensor or conductivity sensor (103), a filter (104), an equipment under test (EUT) (105), a control unit (106), an EUT power supply (107), a water outlet (108), a ballast tank (109), a filter sewage outlet (110), a valve (111), a tubular reverse osmosis (TRO) device (112), a flow detection unit (113) and a pipe, wherein the inside of the filter (104) is provided with a sterilization system; the sterilization system contains a sterilization system consisting of a solid light-emitting diode (LED) ultraviolet lamp and / or a sterilization system combining a solid LED ultraviolet lamp with photocatalysis; and the solid LED ultraviolet lamp is a hollow triangular prism or quadrangular prism type ultraviolet lamp. The device of the invention has the advantages of low power consumption, high efficiency, convenient installation and no pollution.