Through observed over a longer period of time on site of hot strip rolling, found at early stage tension built in closed hydraulic loop often occurred with the phenomenon of large amplitude and highfrequency oscillating, a scheme is put forward that can detect the frequency oscillating of strip tension. The frequency oscillating detected was used to decay gain of tension closedloop efficiently. Through the detection scheme and suppression method, highfrequency oscillating of strip tension set up in machine frame at early stage was effectively prevented, which provided a quite good premise condition for thickness, width and profiles to achieve exam index. The algorithm is put into use in hot strip rolling, and getting good application effect in the scene.