The invention discloses an X-ray beam intensity monitoring device and an X-ray inspection system. The X-ray beam intensity monitoring device comprises an intensity detection module and a data processing module, wherein the intensity detection module is used for receiving irradiation of an X-ray beam and emitting a detection signal; the data processing module is coupled with the intensity detection module to receive the detection signal and output an intensity monitoring signal of the X-ray beam; the intensity monitoring signal of the X-ray beam comprises a dosage monitoring signal of the X-ray beam and a brightness correction signal of the X-ray beam. The X-ray beam intensity monitoring device can carry out dosage monitoring and brightness monitoring simultaneously, and the service efficiency of the X-ray beam intensity monitoring device is improved.