In this paper, ISO 7730 as thermal comfort standard was utilized to analyze the applicability of counter flow dew point evaporative cooler in the dry and hot region—Datong, Shanxi. The output air temperature, cooling efficiency, and cooling capacity were considered, and the finite method was used to optimize the operating parameters and geometric parameters of the evaporative cooler. The effects of primary air inlet velocity, primary-to-secondary air ratio, channel spacing, and channel height on the cooling performance of the system were investigated. The results showed that with the increase of the primary wind speed, both the temperature and cooling capacity of the produced air increase. On the premise that the supply air parameters meet the requirements, the cooling capacity can be increased by increasing the primary wind speed. When working ratio is 0.4 and the channel spacing is 5 mm, the dew point evaporative cooler with the channel height greater than 0.8 m meets the thermal comfort requirement in the range of primary air inlet velocity from 1 to 7 m/s. At the same time, when the heat exchange area is fixed, the greater the length-to-width ratio of the channel, the better the cooling performance.