The invention discloses a swirling air flow powder sieving and collecting system. The system comprises a powder sieving device and a collecting device. The powder sieving device comprises a pedestal and a powder sieving chamber arranged on the upper part of the pedestal and provided with a sealing upper cover, wherein a material inlet formed on the upper cover is communicated with an external powder inlet passage through a valve; double circular clapboards are concentrically arranged on the inner side of the upper cover; a clearance is formed between the two double circular clapboards with the same radius; a sample separating sieve mesh is horizontally arranged in the powder sieving chamber; and after being extended in from the bottom of the powder sieving chamber, an air outlet pipeline of an air filter arranged on the pedestal is communicated with an air nozzle arranged below the sample separating sieve mesh. The collecting device is a sealed powder collecting chamber which is internally provided with a filtering bag, wherein a powder outlet pipeline connected with a powder outlet at the bottom of the powder sieving chamber is extended into the filtering bag from the upside of the sealed powder collecting chamber; and a material collecting pipe connected with an outlet under the sealed powder collecting chamber is communicated with a swirl air pump. The system has the advantages that: the grading effect is clear, equipment is of a simple structure, the specification of the sample separating sieve mesh can be replaced according to needs, and the system is very suitable for laboratory operation.