The invention discloses a method for separating harmonic waves in sleeves in seismic exploration. Median filtering and band-pass filtering are combined by the aid of differences among apparent velocities of seismic waves in the method. The method includes picking up an initial time point and a first time point from original data, adding the initial time point and the first time point of a trace of the original data to time points of various sampling points and leveling upward traveling waves to obtain a first wave field; performing filtering for the first wave field by the aid of an initial time point, a first time point and a second time point of the first wave field to obtain a second wave field; performing Fourier transformation to filter out signals outside frequency bands to obtain a third wave field; subtracting the third wave field from the first wave field to obtain a fourth wave field, picking up a horizontal even in the fourth wave field and performing filtering along a depth direction to obtain a fifth wave field; filtering signals outside frequency bands to obtain a sixth wave field; subtracting the sixth wave field from the fourth wave field to obtain a seventh wave field; repeating the process from a third step to a seventh step once by using the seventh wave field as a first wave field to obtain an eighth wave field; performing filtering by the aid of an initial time point and a first time point to obtain a ninth wave field; subtracting the initial time point and the first time point of the sampling points in each trace from the time points of the sample points to obtain a tenth wave field; and subtracting the tenth wave field from the original data to separate the harmonic waves. The method has the advantages that only seismic waves containing harmonic interference are suppressed, the harmonic waves of the sleeves are effectively separated, and seismic traces without harmonic interference cannot be damaged.