The invention provides a cycloaliphatic polycarbodiimide hydrolytic resistance agent. The cycloaliphatic polycarbodiimide hydrolytic resistance agent has the following structure general formula: the formula is as shown in the specification. The cycloaliphatic polycarbodiimide hydrolytic resistance agent is prepared by a polycondensation reaction (1) and an end capping reaction (2). The cycloaliphatic polycarbodiimide hydrolytic resistance agent is high in softening point, good in heat stability, high in activity, simple and environment-friendly in preparation method, and suitable for biodegradable polyester materials with a lower processing temperature, such as PBAT, PLA, PBS and PHA, and capable of reducing an acid value, effectively inhibiting a problem that the mechanical property is reduced because of the hydrolysis of the polyester materials, repairing a damaged polyester molecular chain, achieving the intermolecular bridging effect, and inhibiting the viscosity reduction of the materials, thereby greatly prolonging the service life of a product. In addition, through adjusting the addition amount of the cycloaliphatic polycarbodiimide hydrolytic resistance agent, the degradation rate and the service life of the biodegradable polyester materials in a natural environment can be controllably adjusted.