The invention relates to a coal bed gas high pressure desorption meter, while the prior coal bed gas high pressure constant temperature adsorption instruments utilizes coal powder samples to test coal bed gas constant temperature adsorption parameters, and the coal bed gas desorption test generally utilizes normal-pressure desorption instruments, to test the parameters of drilling well coal core, such as coal bed gas content and adsorption time and the like. The coal bed gas high pressure desorption meter comprises an automatic temperature control water bath apparatus, a stainless steel mechanical device, and an image and pressure data acquisition system, wherein the stainless steel mechanical device comprises a gas collection cylinder, a sample cylinder, a gas regulation cylinder, a frame, a high pressure pipeline and a valve, the cylinder is fixed on the frame, the frame and the cylinder are arranged in the automatic temperature control water bath device, and the frame is connected with a lifting machine. The invention can effectively simulate reservoir bed conditions and discharge-mining working systems, realize the switch between gas-solid two-phase system and gas-liquid-solid three-phase system under high pressure condition, the desorption, gas collection and measurement processes under high pressure water injection conditions, effectively observe the desorption of coal bed gas, and test the parameters such as desorption pressure, desorption quantity and lost gas quantity and the like.