The invention discloses a dynamic analysis method for a controlled reserves-variable gas well, which breaks through the limitation that a conventional single well dynamic analysis theoretical model and a conventional interpretation method assume that single well controlled reserves is fixed, and accurately analyzes and estimates the change of controlled reserves in a long-term production process of a gas well. The dynamic analysis method comprises the following steps: S1. data segmentation: segmenting according to slope change on a pressure index-total material balance time curve; S2. data regression: selecting an interval according to the real time in segments, performing linear regression, and determining an initial value of phase reserve; S3. gas well iteration: performing material balance correction on gas reservoirs. The invention provides the production dynamic analysis method for the controlled reserves in multiple stages, an analysis mode of dynamic material balance is followed, the variation of the controlled diagnoses is reserved through the slope of a pressure material balance time curve, stage division is performed on multi-controlled reserves analysis data, and segmentdata regression analysis is performed, so that the controlled reserves in each stage is estimated.