A white light source of automotive headlamp based on laser remote activation phosphor with reflective structure is proposed in this paper. Reflective structure of remote-activated phosphor allows the heat be transmitted away in time. Due to the high energy density of the laser diodes’ light， silicon dioxide (SiO2) particles is added to enhance the scatter effect. Through simulation， the quantitative effects of phosphor and SiO2 particles are analyzed and the effeteness of cooling structure is confirmed. According to the design， the prototype of the white light source is made. The test result shows it meet the requirement of being light source of headlamp.