The invention discloses an experiment connector device and method for connecting a DC cable, and belongs to the technical field of novel power transmission and transformation equipment. The device comprises an insulation cylinder, a metal cylinder, a sealing ring, an operation window, a metal crimping pipe and a flexibility-improvement insulator, wherein the insulation cylinder comprises two waterfilling cavities and an oil filling cavity, semiconduction paint is brushed on an inner wall of the oil filling cavity, the two water filling cavities are arranged at two sides of the insulation cylinder, the two water filling cavities and the oil filling cavity are sealed by a sealing cavity, water injection holes are formed in top ends of the water filling cavities, water outlet holes are formed in bottom ends of the water filling cavities, an oil injection hole is formed in a top end of the oil filling cavity, an oil outlet hole is formed in a bottom end of the oil filling cavity, the operation window is used as an opening of the oil filling cavity, the metal crimping pipe is arranged in the oil filling cavity, the flexibility-improvement insulator is wound around the metal crimping pipe, and the metal cylinder sleeves an outer side of the insulation cylinder in a seamless way and is connected with ground. An experiment connector can be used for connecting two segments of the DC cables and can be repeatedly used.