The invention discloses a method of estimating carrier frequency offset for subscriber terminal, including: determining number of effective base stations from which more than one signals are received by a subscriber terminal; combining the signals of each station corresponding to said number of effective base stations; calculating a rough estimation value of the carrier frequency offset based on combined signal. The invention also discloses a device of estimating carrier frequency offset for subscriber terminal, including: decision module, used to determine the number of effective base stations from which more than one signals received by subscriber terminal, combining module, used to combine the signals of the effective base station and output the combined signal to the carrier frequency offset acquiring module; carrier frequency offset acquiring module, used to estimate the carrier frequency offset of the merged signal. According to the invention, the carrier frequency offset for the subscriber terminal will meet system requirement, and improve cell searching success probability.