The invention discloses a coating type crosslinker and a preparation method and application thereof. The coating-type crosslinker is prepared by using toluene-2,4-diisocyanate as an oil-soluble monomer, whiteruss as an oil phase, ethanediamine as a water-soluble monomer, organic acid chrome aqueous solution as a core material and octyl phenol polyoxyethylene (10) ether and sorbitol anhydride monostearate as emulsifiers. A crosslinking polymer system formed by the crosslinker and a suitable polymer has long gelatinizing time and high and controllable gelatinizing strength and can enter the deep part of stratum to achieve the aim of deep profile control or profile modification.