The utility model discloses a sampling valve for a natural gas pipeline. The device comprises a fastening mechanism, a sampling mechanism and a locking mechanism, during sampling, the fastening ring is locked; pipeline looseness caused by unstable air pressure in the natural gas pipeline during sampling is prevented; the rotating crank drives the rotating shaft to rotate; the lead cover falls downdue to gravity to drive the sampling pipe to move downwards; the connecting belt pulls and pulls the lead cover; the sampling pipe extrudes the wall of the telescopic pipe when falling down; the connector can enter the natural gas pipeline for sampling; the wall of the telescopic pipe is clung to the outer wall of the sampling pipe under the pressure action of the spring assembly; after samplingis finished, the crank is rotated; the pressure of the sampling pipe on the telescopic pipe walls on the two sides disappears, and the telescopic pipe walls are closed by the spring assembly, so thatthe natural gas leakage condition during sampling is effectively prevented, the safety of detection personnel is guaranteed under the condition that the normal operation of a natural gas pipeline is not influenced, and oil and gas resources are prevented from being wasted and polluting the environment.