Aiming at nonpremixed catalytic combustion in a threedimensional Yshape microchannel, the numerical simulation study was carried out by using GRIMech 3.0 gasphase reaction mechanism and Deutschmann surface catalytic kinetics. The effects of Pt catalyst coating positions, areas, etc. on the characteristics of the unique combustion phenomenon "flamestreet" in the channel were analyzed. The results show that the burner performance in terms of the methane conversion rate and combustion efficiency, can be significantly improved by coating a certain area of Pt catalyst on the inner walls of channel. In addition, when the catalyst is partially coated on the front portion of the channel walls, the enhancement of the methane conversion rate and combustion efficiency can reach their maximum values by 3.5% and 7%, respectively, which are better than the conditions of fullycoated or partially rearcoated walls.