The utility model relates to a plug valve, in particular to a plug valve with a high-voltage high-frequency switch conical adjustable sealing structure. A valve cavity in a valve body is designed to be conical; the cock and the sealing arc piece are arranged in the valve cavity, and the sealing arc piece is in an outer cone shape matched with the valve cavity. A cock upper sealing ring, a sealingarc piece, a sealing arc piece positioning pin and an arc piece sealing ring are sequentially arranged between the valve cavity and the cock, the sealing arc piece can move up and down along the valvecavity, a first channel and a second channel are arranged on the two sides of the axis of the valve cavity respectively and connected with the valve cavity, and a valve deck is arranged at the bottomof the valve cavity and connected with the bottom of the cock. The plug valve is suitable for oil and gas field operation under pressure, the sealing arc piece and the integrated cock are resistant to abrasion and reliable in sealing, the requirement for high-frequency single-time opening and closing under high pressure can be met, key components are domesticated, and high-efficiency and low-costdevelopment of an oil field is supported.