The utility model relates to a preventing arcing causes complete set distribution device of generating line short circuit and contact box thereof. Said complete set distribution device includes the cabinet body, and the cabinet is internal to have bus-bar room, circuit breaker room, cable chamber and secondary meter room. It is spaced apart completely each other with each room to adopt special technological structure to bus-bar room, circuit breaker room and cable chamber respectively are equipped with independent pressure release passageway. The copper bar of said contact box is directly poured into a mould in the contact box, and it is integrative to make copper bar and contact box constitute, does not have air gap among them. The utility model discloses a complete set distribution device and contact box can effectively be avoided enlarging because of short-circuit fault messenger's accident appears in certain compartment in bus-bar room, circuit breaker room, cable chamber and the secondary meter room, prevent that electric arc from causing the generating line short circuit and causing the master switch tripping operation to have a power failure.