The inducer is a kind of special axial pump, which is widely used in industry communities, such as aerospace delivery systems and medical equipment. Inducer hydraulic performance is impacted sensitively by flow field cavitation. The external characteristic parameters of the turbopump are closely related to the cavitation in the inducer. The generation and changes of the cavitation in the inducer are the root cause of the drop in the turbopump head. The authors first take a low-temperature liquid rocket engine inducer as the research object, bring the numerical calculation and the visual test method to show the law of the generation and change of cavitation in the inducer and its correspondence with the external characteristic parameters of the turbopump, which explain the quantitative correspondence between the cavitation mode of the inducer and the macroscopic external characteristic curves of wheel pumps from a microscopic perspective. The numerical calculation method of cavitation flow field is introduced and the visualization test method is implemented to a proposed platform. The experimental results show that the numerical calculation results are in good agreement with the visualization test results, which indicate that the actual numerical method is practical and feasible for the calculation of the cavitation flow field in inducers. Finally, the pressure fluctuation frequency characteristic is obtained through the experimental and calculation post-process.