An automatic slide cover opening/closing device includes a slide member formed with a guide slot, a base seat slidably connected with the slide member and a power member connected with a conductive contact. An engagement section is disposed on one side of the guide slot. The base seat is formed with a guide hollow intersecting the guide slot. An electrical conductor is disposed on one side of the guide hollow and connected to an external power supply. The power member serves to rotate an engagement member positioned at an intersection of the guide hollow and the guide slot. At least one elastic member is disposed on one side of the power member for elastically keeping the engagement member in abutment with the engagement section. The conductive contact can contact the electrical conductor during a stage of sliding travel of the slide member to power on the power member.