The invention relates to an indoor temperature regulating system capable of performing bionic tree transpiration. The system mainly comprises a roof, a water storage tank and a fractal structure like bionic branches, wherein the roof is mainly formed by a porous medium material layer and a waterproof layer, the water storage tank is used for storing a bionic transpiration water source, and a water conveying pipe which is of a porous structure is adopted in the system. The porous medium material layer is provided with micropores of bionic leaves, one end of the water conveying pipe is connected with the water storage tank, and divergence tips at the other end of the water conveying pipe is connected with the porous medium material layer. According to the indoor temperature regulating system, a cooling principle of tree transpiration is taken as reference, the bionic tree structure is utilized to pump moisture to the roof to perform transpiration and cooling to cool a house, no energy is consumed in the whole cooling process, and indoor temperature adjustment energy consumption is effectively reduced. Besides, when the outer circumstance temperature is low, the transpiration is weak; when the outer circumstance temperature is high, the transpiration is high, and the indoor temperature regulating system has self-adaption characteristics.