By means of test aiming at the three characteristic parameters which influence the performance of cross-flow fan ,derives some results,and carries out statistical analysis on them ,and finally obtains the indensity of impact on.

In this paper,a fundamental working condition and an equation of cross-flow fan are put forward.

In order to study the suction characteristic and the work conditions for fans in series,based on the tests of the single cross-flow fan and the single centrifugal fan,experiment study on the suction characteristic of cross-flow fan and centrifugal fan in series is carried out.

Probed into relation of power and efficiency of two cross flow fans series and single fan, and found speed of fan is fixed in second sequence have more effect to power and efficiency of tw.

On the basis of the previous work, we analyzed the relationships between flow field and cleaning performance and made clear the influences of the changing of the cross flow fan’s location parameters on cleaning performance.

According to the inlet and outlet velocity triangle of cascade,the paper approaches the reason that the bearing of two-grade fan for contra-rotating axial fan is more vulnerable than one-grade fan.

And a method is obtained in selection of an axial fan with minimum power from various type of axial fans.