The invention discloses a dispersion estimation method and device, and an optical receiver, and relates to the technical field of communication. The dispersion estimation method includes steps: calculating a rough dispersion estimation absolute value according to an autocorrelation function of a time domain power waveform of a to-be-estimated signal; determining a dispersion scanning interval according to the rough dispersion estimation absolute value and performing dispersion equalization processing on the to-be-estimated signal; and scanning the processed to-be-estimated signal in the dispersion scanning interval to obtain a maximum and a minimum of a first cost function and corresponding fine dispersion estimation values. According to the method and device, and the optical receiver, rapid and accurate dispersion estimation with large range and high precision can be realized.