With current environmental protection pressure, the optimal environmental protection thinking should be:dust removal is completed by an electrostatic fabric filter and desulfuration is completed by a desulfurizer, each performs its own functions to achieve technical route with highest cost performance during satisfactory emission,and the problem cannot be transferred to the next working procedure. Of course, under such allowable conditions,draft fan capacity, space, sufficient fund, and nearly zero emission, electrostatic fabric filter + electrostatic precipitator are the optimal choice for nearly zero emission.