Drainage gas recovery method for coal-bed gas well and application of drainage gas recovery method

The invention discloses a coal-bed gas well drainage gas recovery method and application thereof. The method comprises five stages of fast flow pressure reduction, flow pressure stabilization, slow flow pressure reduction for production increase, micro flow pressure reduction for stable production and yield decline, or comprises four stages of fast flow pressure reduction, slow flow pressure reduction for production increase, micro flow pressure reduction for stable production and yield decline. And the gas production rate in the slow flow pressure reducing and production increasing stage reaches the optimal production allocation and enters the micro flow pressure reducing and stable production stage. According to the drainage and gas production method for the coal-bed gas well, drainage and gas production stages are reasonably divided, drainage and gas production time can be shortened, high and stable yield for a long time can be determined and controlled, and therefore the overall development benefit is imp