Considering future smart distribution grid (SDG), the protection and control technology of traditional distribution networks is facing new opportunities and challenges. This paper proposes a Multi-Agent System (MAS) based protection and control method for smart distribution grid. The MAS is consist of intelligent distributed terminal (IDT), control master and communication network. Each IDT is regarded as single agent. By information interaction, the IDT is able to fulfill protection, fault location, fault isolation, network reconfiguration, power supply restoration and diagnosis functions. The first part of this paper introduces the structure of SDG, the structure of IDT and the structure of MAS. The second part discusses in detail the new protection method, fault isolation method and supply restoration strategy. In the new protection scheme, the combination of current differential protection and fast current protection is used as main protection. The protection algorithm and operation logic among different agents are analyzed in detail. To evaluate the proposed protection method, the EMTDC based simulation is carried out, which includes modeling of 10kV distribution network with distributed generation (DG), faults simulation on the model and results analysis. The simulation results show that the new protection method is feasible, and the new protection algorithm is correct. The simulation related content is reported in the last part of this paper.