In this paper, the discrete unified gas kinetic scheme (DUGKS) is used to solve the McCormack model of binary gas, simulate the flow and heat transfer of rarefied binary gas between two plates excited by the periodic fluctuation of lower plate temperature, and analyze the effects of system rarefied parameters, temperature change frequency and component molar concentration on the flow and heat transfer between plates. The numerical results show that the gas flow and heat transfer between the two plates change periodically, and we find that the minimum local temperature exists between the plates, and its position is inversely proportional to the degree of system thinning. In addition, it is found that the thermal penetration depth decreases with the increase of the rarefaction parameter. The heat penetration depth first increases with the increase of light component concentration, reaches the highest value when the light component concentration is about 0.6, and finally decreases and is consistent with the result of single component gas.