The invention discloses an outflow optimization device of a pontoon type water-lifting aerator. The outflow optimization device comprises a top ascending cylinder, a middle outflow cylinder, a diversion conical
frustum and a floating body, wherein the floating body is arranged at top of the top ascending cylinder, the middle outflow cylinder is arranged at the center of the floating body, the diversion conical
frustum is arranged at lower end of the middle diversion cylinder, and a plurality of bell mouths of the ascending cylinder are upwards formed in the circumferential direction of the top of the top ascending cylinder among the top ascending cylinder, the floating body and the diversion conical
frustum; and a plurality of drainage holes are formed in the circumferential direction of the side wall of the top ascending cylinder. When a
water flow in the ascending cylinder of the water-lifting aerator is close to an outflow device, part of the
water flow firstly flows out of the side wall of the ascending cylinder, the other part of the
water flow flows out in a radial manner via a channel between the diversion conical frustum and the bell mouths at the top of the ascending cylinder, and the
impact force of the ascending water flow to the water-lifting aerator is reduced by about one half in comparison with an original corresponding value, so that fatigue damages to various connection parts and the floating body at the top of the water-lifting aerator are effectively avoided,
energy loss when the water flow passes through the outflow device is reduced, and long-term efficient and stable operation of the water-lifting aerator is ensured.