The invention relates to a coal rock porosity, permeability and electroacoustic stress-strain combined measuring device under overburden pressure and heating. The coal rock porosity, permeability and electroacoustic stress-strain combined measuring device is provided with an incubator, wherein a supporting rod, a comprehensive gripper, a pushing platform, a cushion block and a coal sample are arranged in the incubator, the upper part of the comprehensive gripper is provided with an experimental oil pipe, the experimental oil pipe is inserted into the coal sample, the upper part of the experimental oil pipe is sequentially connected with an electromagnetic valve e, a standard chamber, a pressure gauge b, an electromagnetic valve c, a barometric regulator and a gas booster pump, an inlet of the gas booster pump is communicated with a gas cylinder through a lead wire, and the upper part of the experimental oil pipe is sequentially connected with a pressure gauge c, an electromagnetic valve d, a water pressure regulator, a liquid booster pump and a water tank. The coal rock porosity, permeability, and electroacoustic stress-strain combined measuring device can be used for effectively simulating the high temperature and high pressure geological environment under deep complicated formation conditions to obtain the porosity, the gas-water relative permeability, a stress-strain curve, the resistivity and the acoustic velocity of the coal rock sample under the same experimental conditions, thus effectively saving the sample, improving the accuracy and the comparability of experimental data, and bringing the great convenience for scientific research.