The embodiment of the invention discloses a color mark tracing method, a color mark tracing device and a color mark tracing system. The method is applied to a transverse cutting machine; the transverse cutting machine comprises a cutter, a conveying belt and a color mark sensor; the method comprises the following steps: setting mounting distance L1 of the color mark sensor and shearing length L; acquiring a color mark total length LA according to a first default rule, the mounting distance L1 and the shearing length L; acquiring running distance LC of one of color mark points after the color mark point is detected by the color mark sensor and the cutter continues to run to a shearing point; determining actual shearing length L2 according to a second default rule, the mounting distance L1,the color mark total length LA and the running distance LC; and controlling the cutter to run according to the actual shearing length L2 so as to enable the cutter to execute shearing when running tothe shearing point once again. According to the color mark tracing method, the color mark tracing device and the color mark tracing system disclosed by the embodiment of the invention, a function of automatically aligning color marks under different shearing lengths can be set onsite, so that production efficiency and shearing precision are increased, waste is also reduced, and production cost isreduced.