The invention discloses a method for networked preponderant gas migration channel construction and gas flow guiding extracting, and the method is especially suitable for active construction of a networked crack channel inside a top plate and gas flow guiding treatment under the condition that the hard top plate directly covers a coal bed. According to the method, a crack generation hole, a crack guiding development hole, a lateral fracturing hole and a crack communicating hole are constructed in the top plate correspondingly in the interior, on the two sides of the front working face of an advance stress variation area, of a roadway. Active construction is conducted inside the hard top plate to form manual guiding cracks. Under the effect of mining-induced stress, the manual guiding cracks and mining-induced cracks are interwoven and pass through mutually to form a networked preponderant gas migration channel. Meanwhile, the manual guiding cracks are drilled to accelerate fracturing of the top plate to form a top plate fracturing separation layer crack area. Gas flows and migrates timely and efficiently along the networked crack channel and is enriched in the top plate fracturing separation layer crack area. Manual guiding crack drilling provides reference for the construction orientation of top plate gas extracting hole drilling, so that gas flow guiding treatment of the mining field is more concentrated and efficient.