In view of the influent water quality fluctuation in the process of sewage treatment, the rectangular wave was used as the fluctuation type under the condition of certain influent mass flow and influent fluctuation period to simulate the equalization process of the water pump forced water quality equalization basin (WPFWQEB) using Fluent. The equalization function coefficient(y) was introduced to the simulation, and then the effects of different reflux ratios (s) and reflux distribution pipe heights (h) on the equalization effect of the WPFWQEB were analyzed. Results indicated that s was the main factor affecting the equalization effect of the WPFWQEB, with the increase of s, the y showed a trend of “rapid growth followed by stabilization”. Firstly, y increased from 0.72 to 0.82 correspondingly with the increase of s from 0.16 to 1.00 in the “rapid growth area”; then s increased gradually to 6.00 and y to 0.92 correspondingly in the “slow growth area”, indicating that the larger the s value, the better the equalization effect; however, after entering the “slow growth area”, the influence of s on the equalization effect was weakened. Further study revealed that the change of h had no significant effect on the equalization effect of the WPFWQEB, because y merely fluctuated from 0.81 to 0.85 when h varied from 50 to 350 mm, which only accounted for 3.7% of the variation range; However, it was worth noting that when h was set as 350 mm , the water mixing and flow velocity in the outlet area were enhanced because the reflux distribution pipe was close to the outlet, in turn y increased slightly to 0.843. So, if it is necessary to improve the equalization effect of the WPFWQEB, priority should be given to adjusting s. This study could provide a theoretical basis for the design and operation of the WPFWQEB.