This invention relates to a vehicle essential oil aroma diffuser, comprising an essential oil bottle containing essential oil of which the upper end is disposed with a lip having external thread； an air guiding cap using the downward opening thereof having an inner wall disposed with internal threads corresponding to the lip to be screwed to the lip, wherein the upper wall of the cap is disposed at one side with an airflow introducing port and at the opposite side with a plurality of discharging holes, and the cap edge at the periphery of the airflow introducing port is protrudingly disposed with a flow guiding wall upwardly； and a bottle sleeve having an upward opening for the essential oil bottle to be sleeved and fixed, of which the external wall is combined with a clipping member. With this structural combination, the clipping member is used to clip the air guiding sheet of the vehicle air conditioning outlet to be fixed, the flow guiding wall of the air guiding cap at the air conditioning outlet is used to guide the cold air to form airflow introducing port to introduce air into the essential oil bottle, and the air is then discharged from the air discharging holes so as to complete the in and out circulation. Accordingly, this invention can effectively guide the essential oil aroma to diffuse to the interior of the vehicle without using vehicle power source or other energy source, therefore, featuring multiple progressiveness including energy saving and carbon emission reduction.一種車內精油薰香器，包括一盛裝精油的精油瓶於上端設一具外螺紋的瓶口，一導氣瓶蓋，以其內壁設有對應瓶口之內螺紋的朝下開口螺結於瓶口，於上壁在一側設一氣流導入口，並在相對側設複數個氣流導出孔，且在氣流導入口外圍的蓋體周邊向上凸設一導流壁，以及一具有朝上開口以提供精油瓶套入固定的一瓶套，於其外壁結合一個夾件；藉此結構組合，由夾件提供夾持於汽車冷氣之出風口的導風片固定，由導氣瓶蓋的導流壁於冷氣出風口外側導引冷氣形成由氣流導入口導入精油瓶內，再由氣流導出孔導出的進出循環，有效導引精油香氣散發於車內，且操作上不需用到汽車電源或其他能源，兼具節能減碳之多重進步性。
