The invention provides an
optimal design method of a cross-flow fan based on an orthogonal test, comprising the following steps of: with a
volute gap, a
volute tongue gap, a circumferential angle inside blades, a circumferential angle outside the blades, the number of blades, the ratio of an inside
diameter and an outside
diameter of an
impeller, a torsion angle of the blades and the like as simulated optimal structural parameters, i.e., test factors, taking n different numerical values, i.e., test levels from each structural parameter; computing performance indexes (air quantity, frequency,
noise and the like) of the cross-flow fan under such a group of structural parameters by using a computational fluid dynamics (CFD) method for each test by using an orthogonal table Lp (p<=30); and finding a group of optimal structural parameters according to
performance index parameters and corresponding weights. If the requirement for performance indexes is very high, n' different test levels for the computed optimal structural parameters can be taken near the value aiming at each test level of the test factors, and then the performance indexes are computed repeatedly by using an orthogonal table Lq to obtain a group of more optimal structural parameters. The method is simple and feasible, low in cost and short in time, and the designed product has good performance.