An idle throttle valve control method of a diesel vehicle, may include a first step of determining whether an idle entry condition of the vehicle may be satisfied, a second step of controlling a throttle valve based on an air amount map and controlling an exhaust gas recirculation (EGR) valve based on an EGR map, when the first step may be satisfied, a third step of determining whether an idle release condition may be satisfied during the second step, and a fourth step of determining whether an EGR return condition may be satisfied, when the idle release condition may be satisfied in the third step.