The invention relates to a coalbed gas dynamic effect simulation system. The system comprises a gas injection system, a sample loading system, a compaction system and an information acquisition system; the sample loading system comprises a high pressure cylinder body which is provided with a plurality of information sensors, one end of the high pressure cylinder body is provided with an exhaust valve and the other end is a sealed pressure plunger; a hydraulic oil chamber is arranged in the hydraulic plunger, a gas inlet tube penetrating the plunger is arranged at the middle part of the hydraulic plunger, and the gas inlet tube penetrates the other end cover; the gas injection system consists of a high pressure bottle, a relief valve, a tube valve fitting and the like, ,and supplies gas tothe gas inlet tube; the compaction system comprises a hydraulic pumping station which injects oil to the hydraulic oil chamber arranged in the hydraulic plunger and provides oil pressure; and the data acquisition of the sample loading, compaction and gas injection processes is controlled by an information acquisition control system. The simulation system can reproduce migration and outburst processes of the coalbed gas, reproduce stress concentration and stress relief processes of coal rock, and can be applied to other related physical effect experimental studies.