The invention provides a separated bunker coal feeding thermal power generating unit coal feeding amount optimized distribution control method. According to the method, a proportional follow control system is used to control the coal feeding amount of each coal mill and add a speed limit module at the coal feeding amount instruction of each coal mill, the control end of each speed limit module is provided with a speed limit bias value setting module, and through setting the output value of each speed limit bias value setting module, the change rate of a poor quality coal feeding amount instruction is lower than the change rate of a good quality coal feeding amount instruction in a total coal feeding amount change. The speed limit module is added in a traditional coal feeding amount control logic, the change rate of each coal mill coal feeding amount and the single control of a change amplitude are realized, the problems of coal mill blockage, coal mill vibration and instable burner burning caused by the large coal feeding amount fluctuation of the coal mill and burner corresponding to poor quality coals in a unit load change process are solved completely, and thus the normal operation of a separated bunker coal feeding thermal power generating unit is ensured.