The invention discloses a carbodiimide oligomer containing steric hindrance, and a preparation method and application of the carbodiimide oligomer. According to the carbodiimide oligomer containing steric hindrance, disclosed by the invention, the raw materials are cheap, and the preparation method is simple, so that the production cost is relatively low, and the carbodiimide oligomer can be extensively applied to the polyurethane industry and can be used for enabling 80% or more of physical properties (i.e., tensile break strength) of a polyurethane product to be maintained after the polyurethane product is hydrolyzed for three weeks (under the conditions that the temperature is 70 DEG C and the relative humidity is 95%) as an anti-hydrolysis stabilizer; the defect that the price of polycarbodiimide products in the prior art is very expensive regardless of high/low melting points is overcome, so that the popularization and application are facilitated; and the carbodiimide oligomer containing steric hindrance is a random copolymer represented by a formula (V) shown in the description.