An insulation termination assembly comprises an insulation tube, an annular bottom plate, and a tail assembly. The insulation tube has an inlet end, an outlet end opposite to the inlet end, and an inner space filled with an insulation liquid. The annular bottom plate is mounted at the inlet end of the insulation tube. The tail assembly comprises an insulation connection tube mounted on the annular bottom plate and a shield tail tube connected to the insulation connection tube. A cable joint of a cable is introduced into the inner space of the insulation tube from the inlet end of the insulation tube after passing through the shield tail tube and the insulation connection tube.