【Objective】Planting catch crops in a protected vegetable field during the fallow season is an important practice to reduce the leaching loss of important nutrients. However, few studies have been done on catch crops with high nitrogen and phosphorus leaching control efficiency in frequent rainfall areas.【Method】This research set up five planting catch crop treatments(sorghum treatment, maize treatment, ryegrass treatment, purslane treatment and collard treatment)and a fallow treatment to study the effect of different kinds of catch crops on nitrogen and phosphorus leaching, NO₃^--N and NH₄⁺-N content and soil microorganism.【Result】The results showed that compared with fallow treatment, sorghum, maize, ryegrass, purslane and collard treatments significantly reduced nitrogen leaching by 12.6, 26.6, 27.4, 28.9 and 26.8 kg·hm^-2 and phosphorus by 0.10, 0.05, 0.04, 0.04 and 0.13 kg·hm^-2, respectively. The nitrogen and phosphorus control efficiency was as follows; purslane＞ryegrass＞collard＞maize＞sorghum, and collard＞sorghum＞maize＞purslane＞ryegrass, respectively. The nitrogen control rates of ryegrass, purslane and collard reached 52.3%, 55.1% and 51.2%, respectively, which were nearly twice higher than the nitrogen control rates of sorghum and maize. This may be because the ryegrass, purslane and collard treatments had a certain coverage in the early fallow period(21 days), which reduced the leaching volume by 23.5%, 17.1% and 26.7% compared with fallow treatment. In contrast, sorghum and maize treatments had poor coverage in the early fallow period, hence there was no significant difference in leaching volume between sorghum and maize treatments and fallow treatment. In addition, the NO₃^--N content in the surface soil(0-20 cm)of ryegrass, purslane and collard treatments was 40.1-52.8 mg·kg^-1, while in the surface soil of sorghum and maize treatments it was 67.8-72.7 mg·kg^-1. Besides, compared with sorghum and maize treatments, ryegrass, purslane and collard treatments also significantly increased the abundance of nirS type denitrifying bacteria in surface soil and nosZ type denitrifying bacteria in rhizosphere soil, which may enhance the denitrification process in soil. This may be one of the mechanisms for high nitrogen leaching control efficiency.【Conclusion】In general, ryegrass, purslane and collard as the catch crops of protected vegetable field in areas with frequent rainfall can significantly reduce nitrogen and phosphorus leaching, and collard has the best effect on nitrogen and phosphorus comprehensive control.