The invention discloses a window-cleaning robot. The window-cleaning robot comprises a walking mechanism, a sampling circuit and a single chip microcontroller, wherein the walking mechanism is used for driving the window-cleaning robot to move on the surface of glass; the sampling circuit is used for sampling current of the walking mechanism at a fixed frequency. The single chip microcontroller comprises a storage module, a computing module and a judgment module, wherein the storage module is used for storing sampling values of the current of the walking mechanism; the computing module is usedfor computing values obtained when the current current sampling value is subtracted from n previous continuous current sampling values, the sum of the values obtained through subtraction, and the accumulated value of the sums of m values obtained through subtraction; the judgment module is used for judging the current walking state of the window-cleaning robot according to the accumulated value.Besides, the invention further discloses a walking state detection method of the window-cleaning robot.