A current-sampling method, comprising: identifying whether a waveform of a current period falls at a boundary of a sector region where a phase current of at least one phase is unable to be collected; determining a first duty cycle and a transforming channel mode for a channel of the at least one phase; storing the first duty cycle and the transforming channel mode in a buffer, and enabling a direct memory access mode to the buffer at the same time; transforming a part of the waveform of the current period by configuring the channel of the at least one phase with the first duty cycle and the transforming channel mode; and acquiring the phase current of the at least one phase based on a transformed waveform of the current period; wherein the method further comprises: identifying whether a waveform of a next period next to the current period falls at the boundary of the sector region; determining that the waveform of the next period should be a standard waveform in response to the waveform of the next period not falling at the boundary of the sector region; and updating the first duty cycle and the transforming channel mode to a second duty cycle and an original channel mode, wherein the second duty cycle and the original channel mode is used to configure the channel of the at least one phase to restore the waveform of the next period. identifying whether a waveform of a current period falls at a boundary of a sector region where a phase current of at least one phase is unable to be collected; determining a first duty cycle and a transforming channel mode for a channel of the at least one phase; storing the first duty cycle and the transforming channel mode in a buffer, and enabling a direct memory access mode to the buffer at the same time; transforming a part of the waveform of the current period by configuring the channel of the at least one phase with the first duty cycle and the transforming channel mode; and acquiring the phase current of the at least one phase based on a transformed waveform of the current period; wherein the method further comprises: identifying whether a waveform of a next period next to the current period falls at the boundary of the sector region; determining that the waveform of the next period should be a standard waveform in response to the waveform of the next period not falling at the boundary of the sector region; and updating the first duty cycle and the transforming channel mode to a second duty cycle and an original channel mode, wherein the second duty cycle and the original channel mode is used to configure the channel of the at least one phase to restore the waveform of the next period. identifying whether a waveform of a next period next to the current period falls at the boundary of the sector region; determining that the waveform of the next period should be a standard waveform in response to the waveform of the next period not falling at the boundary of the sector region; and updating the first duty cycle and the transforming channel mode to a second duty cycle and an original channel mode, wherein the second duty cycle and the original channel mode is used to configure the channel of the at least one phase to restore the waveform of the next period.