The invention provides an experiment method for simulating laser drilling and rock breaking. Biaxial stress is used for simulating stratum stress, a direction adjusting assembly is used for controlling the irradiation position and height of a laser beam and changing the size of spots, irradiated on the surface of a rock sample, of the laser beam, circulating gas is used for simulating the gas circulation atmosphere in laser drilling, and a gas collecting assembly is used for collecting the circulating gas after the experiment so that the physical and chemical reaction of laser-broken rock can be analyzed. Correspondingly, the invention further provides an experiment device for simulating laser drilling and rock breaking. The experiment device comprises a console, an operation desk, the direction adjusting assembly, a laser cutting head fixed to the direction adjusting assembly, a hydraulic system, a sealing unit and a gas collecting unit communicated with a sealed box. According to the experiment method, laser drilling and rock breaking in the stratum can be simulated, and the physical and chemical reaction of the laser-broken rock can be analyzed through the circulating gas; the experiment device is safe and environmentally fixedly; the laser spots can be adjusted more easily and more intelligently, and multiple circulating gas experiment samples can be obtained at the same time.