Abstract:In order to solve the problem of low voltage in the rural power grid,the control measures of voltage regulating device based on the non - contact line of thyristor are proposed. Thyristor step voltage regulator will be treated as two thyristors in inverse parallel connection to a series on the primary side of transformer tap,with the corresponding design of single chip microcomputer control system,the corresponding trigger signals are released to control the set of thyristor,thus it adjusts the transformer winding connecting in primary side to stabilize the input voltage. In the concrete control,in order to prevent the formation of circulation between thyristor switch devices,the corresponding measures need to be found to open the thyristor switch. It is proved that the thyristor step voltage regulator can be used to stabilize voltage.