A sleeve-tightening heat dissipating module includes a pillar, a sleeve, a stand, and heat sinks, wherein the pillar is a cylinder with a wider lower part, and the sleeve can be enclosed at a circumference of the pillar and is provided with a chimb at its bottom rim for allowing the stand and heat sinks to be sheathed on it. As an inner diameter of wider part of the sleeve is smaller than an outer diameter of wider part at lower end of the pillar, the sleeve will be locked on a top end of wider part of the pillar upon assembling. If the sleeve is pressed downward, the sleeve can be expanded outward to tighten the heat sinks, so as to be assembled and fixed with the heat sinks, without a need to paste with a glue, to weld, and to anodize.