For the staged multi-cluster fracturing of horizontal wells, the distribution of fracturing proppant inside different perforations directly affects the placement of proppant in the fracture, which in turn affects the fracturing performance. In order to study the distribution law of fracturing proppant among different perforation clusters along the horizontal wellbore with different influencing factors, we simulate the distribution state of fracturing proppant inside the different perforation clusters over the hydraulic fracturing process by using the Euler-Eulerian method-based computational fluid dynamics (CFD) model. We obtain the distribution law of the proppant among the perforation clusters under different conditions. The simulation results show that the proppant concentration in the bottom perforation is higher than that in the top perforation due to the influence of gravity; while the viscosity of fracturing fluid increases from 5 mPa·s to 100 mPa·s, the concentration difference of proppant in different perforation clusters decreases, which promotes the uniform distribution of proppant among clusters; while the flow rate of fracturing fluid increases from 4.3 m/s to 10.6 m/s, the difference of proppant concentration in different perforations increases, but it is beneficial to the uniformity of proppant distribution in the same perforation cluster; when the proppant density is increased from 1.50 × 10<sup>3</sup> kg/m<sup>3</sup> to 3.00 × 10<sup>3</sup> kg/m<sup>3</sup> and the proppant particle size is increased from 150 μm to 600 μm, the settling rate of proppant is accelarated, the concentration difference of proppant in different perforation clusters is increased, which affects the uniform distribution of proppant among clusters. The findings of this work can be used to guide the design of hydraulic fracturing proppant addition.