The utility model discloses a live-load sealing structure of a plug valve. The live-load sealing structure comprises a plug cock, a valve rod, a valve body, a gland, an upper template, a lower template, a sealing piece, a disc spring, a pressing plate and an adjusting screw. The lower template is located at the upper end of the plug cock and located on the periphery of the valve rod, the upper template is located above the lower template, the sealing piece is located between the upper template and the lower template, between the valve rod and the lower template and between the gland and the valve body at the same time, the disc spring is arranged above the upper template, the pressing plate is arranged above the disc spring, the gland is fixed to the upper end of the valve body, the adjusting screw is screwed in a screw hole in the gland, and the lower end of the adjusting screw abuts against the pressing plate. According to the live-load sealing structure of the plug valve, a sealing pair is additionally arranged compared with the prior art, the live-load structure is additionally arranged, pressure compensation of the sealing pair can be provided, the valve locking phenomenon is prevented.