專利摘要：
A rotary switch state detection device includes a magnetic field generating unit, a gravity sensing unit, a magnetic force sensing unit and a processing unit. The magnetic field generating unit generates a magnetic field. The magnetic force sensing unit and the gravity sensing unit are disposed at a rotary switch to detect a gravity value and a magnetic force value of the magnetic field and generate a gravity strength signal and magnetic field strength signal, respectively. The processing unit is connected to the gravity sensing unit and the magnetic force sensing unit to calculate a gravity value variation and a magnetic force value variation and thereby precisely locate a rotation head of the rotary switch upon completion of rotation thereof.