The invention discloses a start-up circuit with a high-tension power supply, and the start-up circuit comprises a power resistor, an voltage-regulator diode, a current-limiting resistor, an MOS (metal oxide semiconductor field effect transistor) and a filter capacitor, wherein, the negative pole of the voltage-regulator diode is connected with the grid of the MOS, the positive pole of the voltage-regulator diode is connected with the negative pole of an input voltage, the grid of the MOS is connected with a drain through the power resistor and the current-limiting resistor, the source electrode of the MOS is connected with one end of the filter capacitor, the other end of the filter capacitor is connected with the negative pole of the input voltage, the two ends of the filter capacitor are the output ends of the start-up circuit, and the start-up circuit with the high-tension power supply also comprises a capacitor voltage division circuit which consists of at least two stages of voltage division capacitors connected in series; and the capacitor voltage circuit is connected between the positive pole and negative pole of the input voltage in parallel, one end of the last-stage voltage division capacitor is connected with the negative pole of the input voltage, the other end of the last-stage voltage division capacitor is connected with connections of the current-limiting resistor and the power resistor. The start-up circuit provided by the invention has advantages of less loss, high reliability and low cost.