The stiffness of cement stabilized red sandstone soil will change after the addition of biological enzymes, and it is currently difficult to obtain its modulus value. According to relevant specifications, laboratory tests were conducted on the bio-enzyme cement composite solidified red sandstone soil using monotonic loading middle section method, gradual loading and unloading top surface method, gradual loading and unloading middle section method, top surface method dynamic modulus, and middle section method dynamic modulus. The experimental results show that the modulus obtained by the two top surface methods are very close, and the modulus obtained by the three middle section methods are relatively close. The top surface method test results are much smaller than the middle section method test results., and the middle section method test results are more accurate. The monotonic loading middle section test method is easy to operate and analyze, and the results are consistent with other middle section tests. It is recommended to use the monotonic loading middle section method to test the elastic modulus of bio-enzyme cement composite solidified red sandstone soil