Orifice plate type drilling throttling valve

The utility model relates to the technical field of petroleum drilling and exploiting, and particularly discloses an orifice plate type drilling throttling valve. The orifice plate type drilling throttling valve comprises a valve body, wherein a valve cavity is formed inside the valve body, the side portion and the lower portion of the valve cavity are communicated with an outlet pipeline and an inlet pipeline respectively, a fixed valve clack pressed at the port of the outlet pipeline in an abutting mode is arranged in the valve cavity, a rotary valve clack is pressed on the other side of the fixed valve clack in an abutting mode, the corresponding positions of the fixed valve clack and the rotary valve clack are provided with a first throttling hole a and a second throttling hole b respectively, the entity part of the rotary valve clack can completely cover the first throttling hole a, a groove is formed in the other side of the rotary valve clack, and the other end of an elastic valve rod penetrates throug