Modified oxime ester compound, preparation method thereof and photocuring composition

The invention provides a modified oxime ester compound, a preparation method thereof and a photocuring composition. The modified oxime ester compound has any one or more of a general formula I, a general formula II, a general formula III and a general formula IV as follows: the modified oxime ester compound has a large conjugate structure, and the amount of small molecular fragments generated by breakage of oxime ester bonds under ultraviolet irradiation is greatly reduced, so that the probability of failure of light-emitting equipment is greatly reduced, and the service life of the light-emitting equipment is prolonged. The R1 substituent is an aryl or heteroaryl substituent, so that the modified oxime ester compound can be cured at a lower temperature, the performance of accelerating the curing rate of printing ink and the like and improving the photosensitive efficiency of the photoinitiator can be better exerted, and meanwhile, the absorption wavelength of the modified oxime ester compound is further subj