The invention provides an anion generator for nature imitation. The anion generator comprises a container body including an inner cylinder and an outer cylinder sleeving the outside of the inner cylinder. The upper end of the inner cylinder is open to form a container opening; the inner cylinder side wall and the inner cylinder bottom wall encircle a container chamber; and air holes are formed in the bottom of the inner cylinder. A water storage cavity is formed in the bottom of the outer cylinder; an air passage is formed between the outer cylinder side wall and the inner cylinder side wall; an air outlet is formed in the side wall of the outer cylinder; a fan base protrudes from the air outlet; and a fan is installed in the fan base. Besides, an air-flow converter is installed at the container body. With the electric fan, air is exhausted from the container opening through a plant root, the air holes, the air passage, and the air outlet; the part of air exhausted from the air outlet of the fan enters the air-flow converter; and the air is blown to leaves of the planted plant by the air-flow converter to cause friction so as to generate anions; and anions are also generated by using photosynthesis of the plant. The anion generator has advantages of simple structure and low manufacturing and using costs; and only low electromagnetic radiation is caused.