In order to study the influence of recycled fine aggregate substitution on the compressive elastic modulus of regenerated concrete, as well as the quantitative relationship between the cubic compressive strength and static elastic modulus, and to determine the function calculation formula of the dynamic elastic modulus of regenerated concrete based on ultrasonic detection, six groups of prismatic specimens and cubic specimens with different amounts of recycled fine aggregate were made, and the specimens were tested using traditional static test methods and ultrasonic detection methods. The regres-sion equations of the static elastic modulus and compressive strength, as well as the static elastic modulus and dynamic elastic modulus, were obtained by fitting the measured data using the least squares method. A calculation formula for the static elastic modulus of regenerated concrete considering the ad-dition of recycled fine aggregate was established based on ultrasonic parameters. A function relationship formula between the static elastic modulus and compressive strength was also developed. The research results show that the addition of recycled fine aggregate has a significant influence on the dynamic elastic modulus, compressive strength, and static elastic modulus of regenerated concrete, and all of them decrease as the amount of recycled fine aggregate increases.