A boundary protection method and system of a radiation detection robot. The boundary protection method comprises: a first laser radar and a second laser radar are arranged diagonally, a first marking rod and a second marking rod are arranged diagonally; a boundary of an interlocking zone is defined by the first laser radar, the second laser radar, the first marking rod and the second marking rod; the object to be detected is placed in the interlocking zone; the radiation detection robot uses rays to detect the object to be detected in the interlocking zone; an early warning zone is provided outside the interlocking zone; wherein when it is detected that a person or object has intruded into the interlocking zone, the radiation detection robot stops emitting rays; and when it is detected that a person or object has intruded into the early warning zone, a warning is issued directly.