The invention discloses a method for preparing an alkynyl enimic compound containing alpha-H through a one-pot reaction. The method comprises the steps that at the temperature of -78 DEG C, a phosphorus imine compound and acyl chloride containing alpha-H are reacted in an organic solvent to generate corresponding chloro imine which has a coupling reaction with alkynyl copper prepared on site, aftertreatment is carried out, and the alkynyl enimic compound containing alpha-H is obtained. The invention further discloses a compound prepared from the method. The preparation method of the alkynyl enimic compound containing alpha-H is easy to operate, aftertreatment is easy and convenient, substrate designability is strong, the compound of the needed structure can be designed and synthesized according to practical requirements, and practicability is strong. Meanwhile, the compound prepared through the method is good in biological activity, can be used as a raw material to synthesize a heterocyclic compound, and the economic value is high.