SLA is an important guarantee for carrying out cloud services in complex cloud computing environment and the rule of SLA violation compensation can restrict the behaviors of service providers. A variety of possible SLA violation compensation forms are analyzed and the form of mechanism in which service providers report the compensation will is studied in this paper. Based on mechanism design theory, a violation compensation mechanism in which providers would report their real compensation will is designed. The way of choosing service provider, compensation value and decision of service provider is confirmed in this mechanism. The property of incentive compatibility and ex-post individual rationality of the mechanism is also proved in this paper.