Abstract: In order to solve the difficult problem of ion beam spot measurement and profiling in research and adjustment of mass spectrometers, such as low efficiency, tedious process, difficult operation and so on，a method of fast beam spot shape measurement was proposed. Based on the conventional knife-edge method, a multi-angle cutting-line image forming principle was developed. Through sharp knife edge "cutting" ion beam in 0° , 45° , 90° and 135° directions respectively, ion current intensity curves were obtained. Finally, the image of ion beam spot shape and core area could be formed. Through the self-built experimental platform, the ion beam spot shape and core area of this method were compared with that of ion bombardment imaging method. Experiments show that the results of multi-angle cutting-line image forming method are in close agreement with ion bombardment imaging method one. However, this method is of simple operation, time saving and high efficiency, which can realize real-time detection.