The invention relates to the technical field of preparation of cross-linking agents for rubber, in particular to a cross-linking agent, a preparation method of the cross-linking agent and application of the cross-linking agent in rubber preparation. The cross-linking agent is prepared through multi-stage structural design and
functional modification and comprises the following steps: firstly, synthesizing a porous carrier by a template method, loading a
divinyl benzene cross-linking agent after vinyl
silane alkenylation modification, forming inner-layer packaging through Fe < 3 + >-
tannic acid coordination, and performing surface
functional modification by adopting 1, 9-decadiene to obtain the cross-linking agent. And finally, performing outer layer physical
coating through low-melting-point paraffin. The cross-linking agent has a unique dual-threshold gating release characteristic, the outer paraffin provides
physical protection at a mixing temperature, the inner
coordination network is controllably dissociated at a
vulcanization temperature, and on-demand release of cross-linking
active components is realized. When the cross-linking agent is applied to rubber preparation, the uniformity of a cross-linking network can be remarkably improved, the cross-linking efficiency is improved, and the problems that a traditional cross-linking agent is easy to consume in advance, uneven in distribution and the like are solved.