The invention relates to an identification method for a gas reservoir water invasion dominant channel. The identification method comprises the following steps: 1) fitting an influence parameter of a water invasion dominant channel of a target block with a gas-water leading edge propulsion speed, and screening main parameters influencing the gas-water leading edge propulsion speed; 2) calculating aweight coefficient of each main parameter by using a grey correlation method, taking the main parameter screened in the step 1) as a sub-sequence and taking a gas-water leading edge propulsion speedas a mother sequence; 3) after normalization processing is carried out on all main factors, carrying out weighted average, and calculating dominant channel factors; And 4) optimizing the dominant channel factors on each grid in combination with a geological model to obtain a dominant channel body, and determining water invasion dominant channel distribution. According to the identification methodof the gas reservoir water invasion dominant channel, subjective factors in the process of comprehensively comparing a plurality of influence factor geological models in the past are avoided, the goodness of coincidence between the dominant channel factors and dynamic data of a water-breakthrough gas well is good, and the identification precision of water invasion dominant channel distribution ishigh.