Theoretically, the factors affecting the increase of exhaust temperature include intake air temperature, pressure ratio, and compression index (for air compression index K=1.4). The actual conditions affect the high suction temperature. For example, if the intermediate cooling efficiency is low, or the heat exchange is affected by the incrustation in the intercooler, the suction temperature of the later stage must be high, and the exhaust temperature will also be high. Air leakage of the air valve and piston ring will not only affect the rise of exhaust temperature, but also change the interstage pressure. As long as the pressure ratio is higher than the normal value, the exhaust temperature will rise. In addition, for water-cooled machines, lack of water or insufficient water will increase the exhaust temperature.