The invention discloses a material-returning flow manufacturing process for heavy potassium pyrophosphate. The material-returning flow manufacturing process comprises the following steps: step 1, erection of a material-returning flow-line device; step 2, drying treatment in the material-returning flow-line device; step 3, inputting of potassium pyrophosphate; step 4, dust suction and removal; step5, screening treatment; step 6, sorting, conveying and bagging; and step 7, boxing and storage. In the step 1, the material-returning flow-line device is erected at one side of a potassium pyrophosphate production flow line; and in the step 2, before the material-returning flow-line device is used in a material-returning flow, an induced draft fan is energized to work, so a conveyor belt is always in a dry environment. According to the invention, through technical modification, an overall transportation equipment structure is low in cost, so the cost of investment is reduced; through a screening plate, screening of the potassium pyrophosphate with different sizes can be realized, so a product has more regular appearance granularity, facilitates classification for sealed storage and collection, and is convenient for transportation in a later period; and the interior of the flow-line device is dried.