The peak of carbon dioxide emission is the means, and carbon neutrality is the ultimate goal. The peak emission of carbon dioxide is a prerequisite for carbon neutrality. Only by achieving the peak of carbon dioxide emission can carbon neutrality be achieved. The peak time and level of carbon dioxide emissions directly affect the time and difficulty of carbon neutrality: the earlier the peak time, the less pressure to achieve carbon neutrality; The higher the peak value, the faster and more difficult the technological progress and the change of development mode needed to achieve carbon neutrality. The peak of carbon dioxide emission is the means, and carbon neutrality is the ultimate goal. The peak time and level of carbon dioxide emission should be determined under the constraint of carbon neutrality. The lower the peak level, the lower the cost and difficulty of emission reduction; The longer the time from the peak of carbon dioxide emission to carbon neutrality, the less pressure to reduce emissions. Stabilize carbon neutralization and peak carbon dioxide emission through refrigeration technology.