The operational features of the isolated power grid are significantly different from those of large power grids.Especially for the industrial heavy load，the traditional security and stability control measures may not be applicable to the isolated ones.Take the electrolytic aluminum power system as an example.An emergency control optimization method of the isolated power grid with electrolytic aluminum load is proposed.The charactristics and regulation ability of the load are taken into account.Should failure occur，the load transfer is treated as the priority control measure.And the joint control by the power side and the load side is used to solve the problem when a single method cannot meet the requirement of security and stability.With the time domain simulation，the feasible control schemes can be determined.And then the economic cost of load shedding and generator trip is used for the economic assessment of the feasible control schemes.The one with minimum economic cost is treated as the best control scheme.By taking into full account power grid security and stability，the goal of economical operation will be achieved.