Deep hole gas pressure fixed-point measuring system and measuring method thereof

The invention discloses a deep hole gas pressure fixed-point measuring system and a measuring method thereof. The measuring system comprises a hole sealing and pressure measuring assembly and a positioning and supporting assembly, and the positioning and supporting assembly is connected with the hole sealing and pressure measuring assembly; the measuring method comprises the following steps that S1, construction of directional pressure measuring drilling is completed; s2, the positioning and supporting assembly is pushed into the drill hole; s3, the drill rod is slowly withdrawn for the first time, and supporting and positioning are achieved between the positioning and supporting assembly and the drill hole; s4, slowly retreating the drill rod again until the drill rod completely retreats from the drill hole, and enabling the supporting pipeline and the steel wire rope to form a fixed pulley structure in the deep part of the drill S5, cutting off the connection between one end of the steel wire rope and the v