Central draining is often adopted in higher-place aquaculture ponds, and as an important part of the higher-place pond aquaculture system, the draining device at the draining outlet directly affects the draining effects, and thereby affects the success or failure of higher-place aquaculture. In order to solve the problems of traditional draining outlet such as easy blocking and incapability in the suction of pond bottom deposit, a new side-discharge outlet device of SC-1 and SC-2 types, and a top-discharge outlet device SD-1 are designed and tested for the draining effects in actual production. Experiment was conducted to measure the flow velocity and total nitrogen at the draining outlet at different time intervals, and the draining effects of the three new types were studied. The results showed that, at the earlier stage of aquaculture, the draining performance of SC-1 type and SC-2 type draining outlets remarkably preceded the SD-1 type; the total nitrogen draining amount in single count of the side-discharge outlet device was 18.9%（P<0.05）higher than that of the top-discharge type. With the improving of the structure of the central draining outlet, the draining efficiency was significantly enhanced. The research shows that, side-discharge outlet device is of much significance to reduce water exchange rate in higher-place pond prawn culture and achieve the lower water exchange rate aquaculture.