The invention discloses a
petroleum wellhead annular space sealing device. The
petroleum wellhead annular sealing device is used for sealing an annular space between a
wellhead sealing body and a
petroleum pipe, at least one annular groove is formed in the inner wall surface of the sealing body, and the sealing body is provided with an injection hole which is communicated to a centrifugal end of the annular groove; the petroleum wellhead annular space sealing device further comprises a sealing ring, a power ring, and an injection component, wherein the sealing ring is embedded into the annular groove, the sealing ring is used for sealing the groove in the radial direction by being jointed to the wall surface of the annular groove, and is used for sealing the annular space by being jointed to the outer wall of the petroleum
pipe, the power ring is installed in the annular groove and is located between the groove bottom of the annular groove and the sealing ring, and the injection component is installed in an inlet of the injection hole, and is used for injecting fluid with given pressure so as to make the power ring push the sealing ring to tightly press the petroleum
pipe. In the petroleum wellhead annular space sealing device, the requirement for deformation capability of a sealing part is low, and meanwhile the sealing capability can be effectively improved.