Abstract: Multi-layered tight gas reservoir in Shenmu gas field is mainly characterized by vertical development of multiple gas-bearing series,tight reservoir,and low single-well production.Scientific and reasonable optimization of favorable area is an important guarantee for the effective development of such a gas reservoir.In this paper,a comprehensive index method is used,which takes into account many factors,such as reservoir lithology,physical property,thickness of gaslayer and production dynamics.After normalization processing,each influencing factor is given different weights by linear correlation coefficient between the factors and gas production,then,the composite index of each layer is obtained.On this basis,combined with the contribution rate of gas production in different layers,the composite indexes of all layers are weighted and summed,and finally,the boundary of composite indexes is determined by economic evaluation,and the favorable area is predicted.This technical method has been effectively applied in productivity construction of Shenmu gas field.