Abstract: By means of shear simulation, tests of flow parameters and polarized microscopic observation.this paper studied the relation between the influence on the wax crystal and that on the low-temperature flow properties of the PPD-treated wax crude due to the low rate shear. It has been experimentally confirmed that the influence caused by the low rate shear on the wax crystal varies from the different crude. It not only can destroy the wax crystal congeries.but also can prompt their formation. The fluidity recovery during the pipeline flow is essentially the exhibition of the low temperature flow properties improvement of the PPD treated waxy crude due to the low rate shear during the pipeline flow, the mechanism of which is that the congeries.which are broken after high rate shear.gather again under the pipe flow shear.