A phosphor wheel heat-dissipating module for a laser projection system is provided. The phosphor wheel heat-dissipating module includes a phosphor wheel, a plurality of air vents and an impeller. At least one phosphor agent is coated on an outer-ring portion of a first surface of the phosphor wheel. The air vents run through the phosphor wheel. The impeller is disposed on a second surface of the phosphor wheel, and includes an inlet and a first outlet. A laser beam is projected on the outer-ring portion of the phosphor wheel. When the phosphor wheel is rotated at a high rotating speed, an airflow is inhaled into the impeller through the inlet. A first portion of the airflow is blown out through the first outlet, and a second portion of the airflow is transferred to the first surface of the phosphor wheel through the air vents.