Abstract: The conveying process of large sized coals unloaded by the head roller of a TD75 belt conveyor was analyzed. The parabolic trajectory of large sized coals unloaded from the head roller was confirmed by calculating the kinematic trajectory equation, and the area of back plate of head funnel suffered strike severely by flowing coals could be positioned well by using geometric drawing approach based on this trajectory. According to the impact area , the structure of the head funnel was optimized. Two improved structures of head funnel, one with adjustable plate and another with the buffer area of dead coal pile, were designed. The two new improved structures of head funnel both can reduce the force of impact and abrasion resulting from flowing coals and decrease the noise and coal dust.