An one-dimensional planar flame propagation dynamics model in a confined narrow gap of disc shape was developed in this work. And the flame propagation characteristics of combustible mixture in the closed disc-shape narrow gap with the heat loss through walls were studied. The model indicated that wall heat dissipation reduces the flame propagation velocity by reducing the expansion of the high-temperature burnt gas to the low temperature gas, leading to a decrease of the velocity in the flow field across the flame front, and also the flame temperature and the chemical reaction rate. Therefore, increasing the initial pressure or blending reactants with low activation energy such as hydrogen, can effectively reduce the negative effect of wall heat dissipation. The developed theoretical model enriched the theory of flame propagation in micro-scale confined spaces, and also provide corresponding theories and controlling methods for improving flame propagation speed and combustion efficiency.