Abstract: Delay compensation is one of the important components in ensuring the effectiveness of real-time hybrid simulation. Although the inverse compensation method is easy and effective, the delay may often be under-compensated. In this paper, the discrete transfer function of the inverse compensation method is analyzed in the frequency domain, and it is found that the delay compensated by the inverse compensation method has a close relationship with the predicted delay and the frequency of the signal. The compensated delay can be close to the predicted delay when the frequency of the signal is small. Based on the frequency-domain evaluation index, numerical simulation and predefined-displacement tests were conducted, which further prove that there is about 10% difference between α and compensated delay. According to existing real-time hybrid simulation data, it is recommended that the parameter α used in the inverse compensation method should be 1.1 times the predicted value, when the actuator delay is between 10 ms and 30 ms and the frequency is between 0.5 Hz and 3.0 Hz.