Abstract: A CEST data fitting method and apparatus based on an extrapolated semisolid magnetization transfer reference signal, and a medium, which belong to the field of magnetic resonance imaging. According to the CEST data fitting method based on an extrapolated semisolid magnetization transfer reference signal, a lineshape of an MT effect is fused into a Bloch-McConnell equation, the MT effect can be obtained by means of fitting a model that is represented by the equation, and an interference effect can be eliminated by calculating the difference between a curve that is obtained via fitting and a curve that is collected from an experiment. The Bloch-McConnell-based fitting method can take into consideration a radio frequency pulse waveform that is actually used in an experiment, and can also be used when a system is not in steady state.