In order to encourage small-scale power suppliers to effectively share defense data, a measurement infrastructure defense strategy based on sandbox deployment contract theory was proposed. Firstly, an incentive mechanism contract game theory based on information asymmetry was introduced to model the defense data sharing contract between power suppliers. Then, a sandbox deployment contract theoretical model was proposed to improve the defense efficiency of advanced metering infrastructure, ensure the realization of defense data sharing, and reduce the defense cost of traditional power retailers. Simulation results show that the proposed method can effectively realize defense data sharing under the condition of information asymmetry.