Abstract: Based on the model of Ultrasonic signals, this paper designs a frequency-dependent compensation filter to solve the problem, which is the ultrasonic signals' absorb attenuation become higher with the far transmission depth and higher frequencies when transmitting in a tissue. We also transform the operation from the frequency to time to avoid big operation. At the same time, we combine the dynamic filter technique which chose different passband with different depth to hold the high signal-to-noise ratio.