The invention relates to the technical field of daily-use devices, in particular to a valve and an air conditioner. The valve comprises a valve body and a sealing ring, wherein the outer surface of the valve body is provided with a closed annular sealing groove, the sealing ring is of a closed annular structure, an outer contour line of a first cross section obtained by truncating the groove wallof the sealing groove through the plane of the axis of the sealing groove is arc-shaped, the outer contour line of a second cross section of the outer surface of the sealing ring cut by a plane is round, and the radius of the first cross section is smaller than or equal to the radius of the second cross section. The valve provided by the invention can basically ensure the relatively high sealing connection effect between the sealing ring and the sealing groove after the valve is used for a period of time or is used at a low-temperature environment, so that the situation that the sealing failure of the valve is caused is avoided.