The invention relates to a sectional cooling system of a belt type roasting machine. The sectional cooling system of the belt type roasting machine comprises a belt type roasting machine body, the belt type roasting machine body is divided into an forced air drying section, a down-draft drying section, a preheating section, a roasting section, a soaking section and an blast cooling section along the material flow direction, an air bellow is divided into four, the sectional cooling system of the belt type roasting machine further comprises a first air blower, a second air blower, a cooling exhaust fan, a silencer, a temperature measuring device I and a temperature measuring device II, wherein the blast cooling section is divided into a blast cooling front section, a blast cooling rear section and a down-draft cooling section, and the fourth air bellow is divided into a blast cooling front section air bellow, a blast cooling rear section air bellow and a down-draft cooling air bellow. The sectional cooling system of the belt type roasting machine has the advantages that airflow direction of the blast cooling rear section penetrates through a material layer from top to bottom, the cooling effect is improved, the cooling speed is increased, the belt type roasting machine utilization rate is increased, the service life of a finished belt type roasting machine is prolonged, power consumption of a cooling fan is reduced, and heat exchange conditions of the forced air drying section are improved.