Power tube power supply circuit and power tube testing device

The invention discloses a power tube power supply circuit and a power tube testing device. The circuit comprises a key control circuit, a main controller, a charge switch and an energy-storage capacitor, wherein a plurality of key signal input ends of the main controller are connected with a plurality of key signal output ends of the key control circuit in a manner of one-to-one correspondence; afirst control end of the main controller is connected with a controlled end of the charge switch; an input end of the charge switch is used for being connected to a high-voltage DC power supply; an output end of the charge switch is connected with the energy-storage capacitor; the key control circuit is used for receiving a key instruction input by a user and outputting a key signal correspondingto the key instruction to the main controller, so that the main controller sets charging threshold voltage according to a voltage key signal, controls the charge switch to be turned on to trigger charging of the energy-storage