The invention provides a combustion optimization system and adjustment method for preventing water wall high-temperature corrosion. The combustion optimization system comprises air and pulverized coal adjustment devices, secondary air distribution adjustment devices, two water wall near wall region smoke component measuring devices, a plurality of auxiliary over fire air nozzles, a temperature field measuring device and a coal economizer outlet smoke oxygen content field measuring device. A first air and pulverized coal pipeline corresponding to each combustor is provided with the corresponding air and pulverized coal adjustment device. Each secondary air box is internally provided with the corresponding secondary air distribution adjustment device. The two water wall near wall region smoke component measuring devices are separately mounted on the water wall on the two sides of a boiler. The multiple auxiliary over fire air nozzles are separately arranged below over fire air nozzles. The temperature field measuring device is arranged on the portion, below a platen overheater, in a hearth. The coal economizer outlet smoke oxygen content field measuring device is arranged at a coal economizer outlet flue. By adoption of the combustion optimization system, high-temperature corrosion to the water wall of the opposite cyclone combustion boiler can be effectively relieved.