A server power supply device and method are provided. The server power supply device includes: a filter capacitor, a voltage collecting unit and a processing unit. One terminal of the filter capacitor is connected to a mains electricity input terminal, the other terminal of the filter capacitor is grounded, and a capacitance of the filter capacitor is greater than a preset standard capacitance. The voltage collecting unit is connected to the mains electricity input terminal and the processing unit, and the voltage collecting unit is configured to collect a first voltage inputted from the mains electricity input terminal. The processing unit is configured to process a current inputted from the mains electricity input terminal based on the first voltage collected by the voltage collecting unit, to generate a first current and supply power to a server with the first current.