Disclosed are a magnetic molecular imprinting photonic crystal sensor, a preparation method therefor and the use thereof. A non-ionic amphiphilic random copolymer is used; an emulsifier from a fine emulsification system, a coating material of magnetic nanoparticles and a molecularly imprinted material of a sensor are integrated into a whole product; and the magnetic molecular imprinting photonic crystal sensor is prepared by means of a one-step method. The problem of the preparation process of an existing molecular imprinting photonic crystal sensor being complex and tedious, time-consuming, labor-consuming and expensive is solved. Moreover, a magnetic response photonic crystal based on a steric hindrance effect is constructed by means of the method, so that defects based on an electrostatic repulsion system are overcome, the interference of ion strength, pH, etc., on a solution to be tested is eliminated, and the practical application of the magnetic molecular imprinting photonic crystal sensor is broadened. The response speed of the photonic crystal sensor is improved due to the advantage of surface imprinting, and the effect of simple, convenient and rapid “naked eye detection” is achieved.