Based on the analysis of agricultural technology, climate and fertilizer condition for rice planting in South China, a new kind of fertilizer deep applicator is developed. This machine adopted a new principle for fertilizer application, i. e., the fertilizer to be applied is mixed with some water first, then a screw mechanism is used to make the mixture of fertilizer and water enter soil through a pipe. The machine can overcome jam, adhesion and impracticableness of fertilizer. Experiment results show that the machine has high flexibility and credibility, and the remarkable function of saving fertilizer and increasing economic income in rice planting.