The present invention relates to a multi-phase voltage regulator and a temperature monitoring method thereof. The method includes the following steps of: step 1a: providing a multi-phase voltage regulator including a controller and a plurality of power stages, wherein the controller transmits a corresponding control signal to each of the plurality of power stages, each of the plurality of power stages including a temperature sampling unit, outputs of the temperature sampling units connected to the controller and in parallel with each other; Step 1b: performing time-sharing signal exchange with the temperature sampling unit of the power stages; and Step 1c: when the controller exchanges signals with the temperature sampling unit of a certain power stage, the temperature sampling unit transmits an output signal representing the temperature thereof to the controller via the output.