A three dimensional printing apparatus configured to print a three dimensional object, comprising: a base having a carrying surface; a printing head module disposed above the base, comprising: a printing head comprising a heating element, a feeding channel and a nozzle, wherein the feeding channel comprises a plurality of heat dissipation fins disposed on an outer surface of the feeding channel, the feeding channel connects the nozzle, and the heating element is configured to heat the nozzle; a fan disposed correspondingly to the feeding channel to provide an airflow; a feeding guiding cover connected to the feeding channel, and located between the fan and the feeding channel; a nozzle guiding cover disposed correspondingly to the fan and extended to the nozzle, wherein the nozzle guiding cover comprises a nozzle outlet, the nozzle outlet is located between the nozzle and the carrying surface; and a controller electrically coupled to the printing head module to control a hot-melt material transmitting from the feeding channel to the nozzle, wherein the heating element is configured to heat the nozzle so the hot-melt material is hot-melted and extruded, and the hot-melt material is dispensed on the carrying surface to form the three dimensional object, the controller controls the fan to provide an airflow, and the airflow is guided from the heat dissipation fins to the nozzle outlet of the nozzle guiding cover, the three dimensional printing apparatus being characterized in that the airflow flows through the feeding channel, the feeding guiding cover and the nozzle guiding cover along a direction perpendicular to an axial direction of the feeding channel. a base having a carrying surface; a printing head module disposed above the base, comprising: a printing head comprising a heating element, a feeding channel and a nozzle, wherein the feeding channel comprises a plurality of heat dissipation fins disposed on an outer surface of the feeding channel, the feeding channel connects the nozzle, and the heating element is configured to heat the nozzle; a fan disposed correspondingly to the feeding channel to provide an airflow; a feeding guiding cover connected to the feeding channel, and located between the fan and the feeding channel; a nozzle guiding cover disposed correspondingly to the fan and extended to the nozzle, wherein the nozzle guiding cover comprises a nozzle outlet, the nozzle outlet is located between the nozzle and the carrying surface; and a controller electrically coupled to the printing head module to control a hot-melt material transmitting from the feeding channel to the nozzle, wherein the heating element is configured to heat the nozzle so the hot-melt material is hot-melted and extruded, and the hot-melt material is dispensed on the carrying surface to form the three dimensional object, the controller controls the fan to provide an airflow, and the airflow is guided from the heat dissipation fins to the nozzle outlet of the nozzle guiding cover, the three dimensional printing apparatus being characterized in that a printing head comprising a heating element, a feeding channel and a nozzle, wherein the feeding channel comprises a plurality of heat dissipation fins disposed on an outer surface of the feeding channel, the feeding channel connects the nozzle, and the heating element is configured to heat the nozzle; a fan disposed correspondingly to the feeding channel to provide an airflow; a feeding guiding cover connected to the feeding channel, and located between the fan and the feeding channel; a nozzle guiding cover disposed correspondingly to the fan and extended to the nozzle, wherein the nozzle guiding cover comprises a nozzle outlet, the nozzle outlet is located between the nozzle and the carrying surface; and a controller electrically coupled to the printing head module to control a hot-melt material transmitting from the feeding channel to the nozzle, wherein the heating element is configured to heat the nozzle so the hot-melt material is hot-melted and extruded, and the hot-melt material is dispensed on the carrying surface to form the three dimensional object, the controller controls the fan to provide an airflow, and the airflow is guided from the heat dissipation fins to the nozzle outlet of the nozzle guiding cover, the three dimensional printing apparatus being characterized in that the airflow flows through the feeding channel, the feeding guiding cover and the nozzle guiding cover along a direction perpendicular to an axial direction of the feeding channel.