A UV liquid gel solidifying device includes a support member, a UV LED module, a top cover, and a base. The UV LED module is installed on the support member and emits light into a first chamber of the support member. The support member is disposed on the base, and the base has a third chamber defined there beneath. The top cover is assembled on the support member and has a slide cover slideably mounted thereto. When the slide cover moves toward a first direction, the first open end and the second open end are opened so that the user's fingernails can be put in the first chamber for treatment. When the slide cover is released to revert back to close the first open end and the second open end, the user's eyes can avoid from being directly exposed to the UV light. When the toenails are to be treated, the base can be conveniently disassembled from the support member, and the toenails to be treated are inserted into the first chamber for treatment.