To address the need for rapid measurement of elastic modulus in aerospace materials，a line-focused sensor was used to perform defocusing measurements on the material surface，simultaneously capturing ultrasonic longitudinal waves and leaky surface waves.Based on the linear relationship between defocusing distance and the time difference of leaky surface waves and reflected longitudinal waves，the elastic modulus of the material was characterized.A scanning mechanism was designed using a three-degree-of-freedom precision motion platform，integrating a high-frequency ultrasonic excitation/receiving module and a high-speed data acquisition module.Ultrasonic measurement software for elastic modulus was developed，resulting in a fully automated ultrasonic elastic modulus measurement system.Measurement experiments on aluminum-lithium alloy and nickel-based alloy were conducted to determine their mechanical properties.The results indicate that the proposed method and developed system not only achieve measurements of elastic modulus and Poisson''s ratio for the two typical materials，but also obtain their shear modulus and bulk modulus parameters.The deviations of the elastic modulus measurements from reference data are 0.45% and 1.51% for the two materials，respectively.This research demonstrates that the developed technology offers advantages of rapid and non-destructive measurement of material mechanical properties，providing support for new material development and structural performance evaluation.