The invention discloses a compound hydrate inhibitor based on piperidine ionic liquid. The compound hydrate inhibitor is characterized by comprising the piperidine ionic liquid, a kinetic inhibitor and water, wherein the structural formula of the piperidine ionic liquid is as shown in the formula I (the formula can be found in the specification), R2 and R2 are C1-C4 alkyl substituent, and X- is tetrafluoroborate; the kinetic inhibitor is polyethylene caprolactam; with the water-based mass formed by hydrate in the raw materials as the benchmark, the mass concentration of the kinetic inhibitor polyethylene caprolactam is 0.5-1 wt%; and the mass concentration of the piperidine ionic liquid is 0.5-1 wt%. The compound hydrate inhibitor has the advantages of being better in inhabitation effect, small in consumption and wider in application; and the hydrate inhabitation requirement can still be met under the condition of a high undercooling degree and low consumption of 1-2 wt%, the inhabitation cost is greatly lowered, and the damage to the environment is reduced.