A method for controlling power supply through multiple modulation modes aims to control an inverter of a selective characteristic through a cycle control signal of varying modulation modes to ensure that the inverter and the load on the rear end function in a reliable characteristic range and prevent the load from aging too quickly. The method includes generating a cycle control signal which includes ON-Time and OFF-Time, and adding a regulation energy of varying amplitudes or frequencies in the OFF-Time to provide varying modulation modes by mixing duty cycle, frequency modulation and amplitude modulation. The power supply can be controlled with a high reliability and a wide dynamic range.