The invention discloses a comprehensive testing device for coal bed strain, seepage, displacement and flow jetting. The comprehensive testing device comprises a coal core chamber, a vibrator, an ultrasonic wave generator, a methane gas source, a seepage and displacement gas source, a hand rocking pump, a specific resistance determinator, a gas storing tank, a gas control valve, a bursting disc assembly, a releasing cylinder, a pressure sensor, a high-pressure valve, a drying agent, a gas flowmeter, a strain measurement sealing container and a strain gauge. Meanwhile, the invention further provides a comprehensive testing method for coal bed strain, seepage, displacement and flow jetting. The method comprises the steps of equipment leakage testing, high-pressure gas seepage testing, high-pressure gas displacement testing, high-pressure gas flow jetting testing, specific resistance determining testing and high-pressure strain measuring. The comprehensive testing device is used for carrying out testing of successfully cracking a coal sample after gas seeps a coal core, meanwhile, coal sample gas displacement testing, specific resistance determining of the coal core under high pressureand gas seeping, and coal bed high-pressure strain measuring can be carried out, and therefore the test result is closer to the true situation.