The invention relates to a discharge and recovery device and method, belongs to the technical field of coal bed methane development and particularly relates to a two-coal-bed four-channel packer layered pressure controlling combining discharge and recovery device and method. Two coal beds are packed in different pressure systems, a liquid passing pipe is connected on the upper portion of a liquid passing channel of the upper coal bed, a certain liquid level depth can be kept, and even if the wellbore liquid level is lowered below the upper coal bed, upper coal bed explosion is not caused, so that under the condition that the best gas production effect of the lower coal bed is guaranteed, the best gas production effect of the upper coal bed is still guaranteed, reservoir damage is reduced, and interlayer interference in the two-coal-bed discharge and recovery process is reduced.