As a result of the remarkable effect of the distribution of sprinkler water by crop canopies, the distribution uniformity of sprinkler water is changed evidently from the space to the ground. By the trials for the spring maize, the phenomenon is discussed that the distribution of the sprinkler water is the upside and the underside of maize canopies in different growth periods. The maize canopy changed distribution of sprinkler water near the ground. When sprinkler water reached the maize canopy, the sprinkler water fell down with four ways, namely, stem-runoff water, leaf-needle water, under-leaf water, row-space water respectively. Their distribution uniformity was very good in the basic points themselves. However, as a whole, the re-distribution uniformity of sprinkler water was bad by the effect of maize canopies. Obviously, it is not ignored for the distribution of the sprinkler water by the canopy. It is important that the mechanism of the effects between them is researched accurately.