Provided is a production process for powdered sugar and liquid syrup, comprising the steps of primary pressing sugar cane juice extraction, three-stage physical filtration, and sugar boiling, wherein the step of the three-stage physical filtration respectively uses a sieve plate, a bagasse separator and a micro-filtration membrane for filtration. The bagasse separator comprises a screen cylinder transversely arranged inside a separation bin. The inlet and outlet of the screen cylinder are respectively connected to a feeding bin and a discharging bin. A juice outlet and a bagasse outlet are respectively provided under the separation bin and the discharging bin. A propeller blade component is provided inside the screen cylinder. The propeller blade component is formed by combining vertical mixing blades with helical blades.