We present a systematic study of dynamic hysteresis in ferroelectric spin systems by Monte Carlo simulation based on the ferroelectric DIFFOUR model, Sawyer-Tower hysteresis measurement of YBa₂Cu₃O₇(YBCO)PbTi_0.48 Zr_0.52O₃ (PZT)/YBCO thin film capacitors and the phenomenological approach to the (Φ²)²-model system. The hysteresis area A as a function of frequency f of the external field E is single-peaked, due to the full spin relaxation at low f and suppressing effect at high f for the domain switching. It is revealed from the simulation that the hysteresis area A can be scaled with a dynamic scaling function A(f)/A_m = F(x), which is symmetric to x = 0, where x = log(f/f_m) with f = f_m the position of the peak A_m = A(f_m). The scaling gets support from the experiment and is consistent with the prediction of the (Φ²)²-model.