The invention discloses a coal bed gas multi-machine linkage hydraulic drive discharge and recovery process system and belongs to the field of coal bed gas exploitation. The coal bed gas multi-machine linkage hydraulic drive discharge and recovery process system comprises a ground hydraulic pump station, a power liquid conveying control system and a downhole oil well pump unit. The ground hydraulic pump station conveys power liquid to the downhole oil well pump unit through the power liquid conveying control system. The downhole oil well pump unit is driven to work so as to complete discharge and recovery of well liquid, reduce the pressure of a well bottom and achieve recovery of coal bed gas. The hydraulic drive rodless discharge and recovery system is adopted, the problem of uneven abrasion of three-pumping discharge and recovery system rod pipes is solved fundamentally, and the advantages that parameter adjusting is convenient and the parameter adjusting range is large are achieved; multi-machine linkage on the same platform can be achieved, multiple machines does not interfere with one another, and the discharge and recovery cost is reduced greatly; the power liquid circulation mode adopts closed-type circulation, the power liquid and production liquid of a coal bed gas well are not mixed but return to the ground through respective channels; and the failure rate of the hydraulic system due to power liquid pollution is decreased, and the system efficiency is improved.