The application of engineering control theory in weather modification process and its modeling are studied. Although weather modification has been developed for more than 60 years and has great achievements, there are still many scientific and technical problems to be solved, typically as the blindness of operation and the evaluation. Control theory studies how to manipulate action on the system to make it hold the given behavior. The authors introduce engineering control theory in weather modification, educe the “local control” method, and take the cold cloud seeding as an example. The first order plus dead time model is employed to simplify the seeding-nucleation process for one cloud mass and the frame model of cold cloud seeding process with feedback is established. This model adjusts the seeding rate according to the effects, so that key parameters of the rain clouds could achieve the desired values. The “local control” method also can be embedded in the global system controlling action (the natural cybernetics) to simplify the operation.