A heat dissipation module is configured to dissipate heat generated by at least one heating element of a projection device. The heat dissipation module includes at least one first heat pipe, at least one second heat pipe and a heat dissipation fin assembly. The first heat pipe includes a first section connected to the heating element and a second section. The second heat pipe includes a third section connected to the heating element and a fourth section. The length of the first heat pipe is less than that of the second heat pipe. The heat dissipation fin assembly includes a plurality of heat dissipation fins. The second section and the fourth section pass through the heat dissipation fin assembly, and the number of heat dissipation fins through which the second section passes is 70% or below of the number of heat dissipation fins through which the fourth section passes.