A wavelength conversion module includes a wavelength conversion wheel, a driving assembly, thermal conductive adhesive structures, and a deflector. The wavelength conversion wheel includes a rotatable disc and a wavelength conversion layer. The driving assembly is connected to the rotatable disc, and the wavelength conversion layer and the thermal conductive adhesive structures are respectively located on two opposite sides of the rotatable disc. The deflector is connected to the wavelength conversion wheel along the axis through the thermal conductive adhesive structures. Heat dissipation channels are formed among the deflector, the rotatable disc and the thermal conductive adhesive structures. An air inlet is defined by each of the heat dissipation channels and the deflector near the axis, and an air outlet is defined between each of the heat dissipation channels and a periphery of the deflector. An area of the air inlet is larger than an area of the air outlet.