The invention relates to an apparatus for measuring a soil erosion gully and aims to provide the apparatus capable of measuring the penetration depth of a slope or a curved surface in a certain range. The apparatus can directly measure the erosion amount of the slope and has the characteristics of high detection precision, high detection efficiency and high automation degree. The invention adopts the technical scheme that: a portable laser water and soil loss monitor with a corner structure comprises a singlechip, a Bluetooth communicator, a battery and a laser distance meter. The portable laser water and soil loss monitor is characterized by also comprising a supporting frame and a measuring head, wherein the measuring head comprises a supporting shell, a sensor bottom plate and a swing mechanism, wherein the supporting shell comprises an upper shell and a lower shell; the upper shell and the lower shell are cylindrical and jointed up and down; axes of the upper shell and the lower shell are overlapped; a horizontal rotary motor is fixedly arranged in the lower shell; an output shaft of the horizontal rotary motor vertically extends upwards; and a rotary main shaft matched with the output shaft in an inserting way can be rotationally and vertically arranged in the upper shell.