Taking Haoda water-soluble fertilizer containing humic acid produced by Wuhan Haoda Agricultural Science and Technology Co., Ltd., as the material, a formal field plot test was carried out in a citrus orchard with an altitude of more than 600 m, and the application effect of this fertilizer on citrus was verified. The results showed that the effect of 1000 times liquid spray or spray + root irrigation on the yield and income of citrus was significant, which increased 75.4 kg and 99.4 kg, respectively, by 6.57% and 8.66%, compared with the conventional fertilization, and the net income per mu was 868.8 yuan and 596.8 yuan, respectively; compared with the conventional + clean water spray, the yield increased by 64 kg and 88 kg, 5.52% and 7.59% respectively, and the net income increased by 732 yuan and 460 yuan respectively. The fertilizer can promote the fruit setting of citrus to some extent, and the shoot germination in spring, summer and autumn; with the increase of application times, the number of shoots in summer and autumn increased gradually. The fertilizer can also promote the expansion of citrus fruit and increase the weight of single fruit, reduce the number of small fruit and increase the number of large fruit, so as to achieve yield increase.