Fertilizing fish farming is a small-scale intensive farming. One of the important measures to increase fish production is to cultivate natural bait in ice city. Fish are fed at the water supply station. Fertilization can also improve the living environment of fish and drift organisms through biological, chemical and chemical actions. Some organic fertilizer components can also be directly used as nutrients by fish in reservoirs. Rational fertilization is the basic requirement of fertilization in fish farming. So how to apply fertilizer reasonably? Briefly introduce the following points: 1. Types of fertilizers: Fertilizers for sequential fertilization can be divided into organic fertilizers and inorganic fertilizers, including livestock manure, human urine and green manure. Inorganic fertilizer is commonly known as chemical fertilizer, including nitrogen fertilizer, phosphorus fertilizer, calcium fertilizer and compound fertilizer. Because the water sequence is different from the pond, the water exchange flea in the water sequence is large, the water level is unstable, and the water is deep, so it is best to apply quick-acting inorganic fertilizer when fertilizing fish. The uniform slow effect of organic fertilizer makes up for the short validity period of inorganic fertilizer, so the application effect of both is better. 3. Fertilization time: Generally, more organic fertilizer should be applied in early spring, and more inorganic fertilizer should be applied when the 6eeg water temperature rises in June. Fertilization should be based on the special growth of plankton in the water and the feeding situation of fish, and choose the season with small water exchange capacity, short water exchange time and stable water level ... (This paper has 2 pages).