A method of assembling thermal module includes steps of providing a first heat dissipation member and a second heat dissipation member, and aiming a section of the first heat dissipation member at a section of the second heat dissipation member, which section of the first heat dissipation member is to be assembled with the section of the second heat dissipation member and driving the first heat dissipation member to connect with the second heat dissipation member by means of striking the first heat dissipation member into the second heat dissipation member. By means of the method, the thermal module can be assembled at higher efficiency. Moreover, the manufacturing process of the thermal module is simplified.