In order to solve the problem of the unclear understanding of the water cone behavior and its influencing factors of horizontal well in a heavy oil reservoir with bottom water, in this paper, a series of physical models were established to quantitatively describe the inner relationships between them and further illustrated their influence on the water-cut increasing law. The results showed that the water cone and water-cut grew quickly in the heavy oil reservoir with bottom water. The sweep efficiency of the basic 2D sand-pack model reaches 0.68. The decrement of crude oil viscosity increases the sweep efficiency to about 0.08. The increment of production pressure drop increases the sweep efficiency to about 0.05–0.07. Heterogeneity enhancement decreases the sweep efficiency to about 0.06. The addition of adjustment well and barriers increases the sweep efficiency to about 0.20 and 0.08, respectively. The final sweep efficiency of the whole water cone in the 3D sand-pack model reaches 0.42. Finally, we found that the water-cut increment rules are mainly affected by water cone behavior, production schedule, and the location and distribution of barriers. The study in this paper lays a foundation for the rational and effective development of heavy oil reservoirs with bottom water, which has a broad field application prospects in the future.