Device for sealing material of mixing drum and agitating truck

The invention provides a device for sealing material of a mixing drum and an agitating truck. The device for sealing material of the mixing drum comprises the following parts: a feed hopper which is hinged to a fixed pedestal and used for feeding to the mixing drum; a close cover which is used for covering a discharge hole of the mixing drum and rotating with the mixing drum and is provided with an opening; a rotating member comprising an inner ring and an outer ring, the inner ring and the outer ring coaxially rotate relatively, the feed hopper is fixed connected with the inner ring, the cover is fixed connected with the outer ring, or, the feed hopper is fixed connected with the outer ring, the cover is fixed connected with the inner ring, and the feed hopper is communicated with the mixing drum through the inner ring and the opening; and a drive unit for driving the cover to open or close the discharging hole of the mixing drum. According to the invention, the central portion of the cover is provided with the opening for the feed hopper to passing through, and the cover can rotate with the mixing drum, so that the wearing between the cover and the mixing drum is avoided.