The invention discloses a method for determining a crosstalk value of a multi-core optical fiber. The method comprises the following steps: acquiring a parameter value of the multi-core optical fiber;calculating a coupling coefficient between fiber cores of the multi-core optical fiber according to the parameter values; dividing the multi-core optical fiber into optical fiber sections with presetlengths; calculating a first crosstalk value of each optical fiber section according to the coupling coefficient and the parameter value; and determining a first crosstalk value of the multi-core optical fiber according to the first crosstalk value of each optical fiber section. Compared witht the prior art that a discrete change model is used to calculate a crosstalk value, the crosstalk value does not need to be regarded as a random variable and is taken as a value accumulated linearly along the optical fiber lenghth, the crosstalk value is only increased in the phase matching area, the crosstalk value is hardly changed at the non-phase matching point, and the crosstalk value calculation accuracy is greatly improved when the method is applied to the multi-core optical fiber of which thebending rate and the bending radius are not constant. The invention also provides a system and equipment for determining the crosstalk value of the multi-core optical fiber, and a readable storage medium, which have the above beneficial effects.