The invention discloses a collection device for residual insulating oil in a sampling container, which relates to the field of power tools, and solves the technical problems that the insulating oil is wasted in a treating process of the insulating oil container and a plenty of detergents and a large amount of washing water need to be consumed in the prior art. The collection device provided by the invention comprises a stander, wherein a box body with an opening in the top is arranged on the stander; a supporting frame for supporting the inverted container is arranged in the box body; a flow collection groove with an inverted cone-shaped longitudinal section is formed in the bottom of the box body; a drainage opening is formed in the bottom of the flow collection groove. The collection device is applied to reuse of the residual insulating oil in the container.