OFDM system is sensitive to CFO (carriers frequency offset) which is divided into fractional part and integer part. In usually, estimation of integer CFO needs to store one OFDM symbol. However, the maximum length of FFT in DVB-T is 8192, so it requires a lot of storage units. In this paper, we propose a memory reduction algorithm for integer CFO estimation used in DVB-T. This memory reduction algorithm reduces the usage of the continual pilots and only sign bit is stored. Thus, the usage of memory is reduced by 90%, the access number is reduced by 94% and the estimation time is reduced by 37%.