As one of the important components of ethylene plant, debutanizer system directly affects the long-term, safe and stable operation of ethylene plant and downstream production units. This paper mainly introduces the influence of different tower pressures on debutanizer system. It is very important to select appropriate tower pressure for the operation and energy saving of tower system. The specific effects of different feeding positions on debutanizer system are further studied, and reasonable suggestions on the optimal feeding position are given. At the same time, the influencing factors of system operation are analyzed in detail, which is helpful to realize the long, stable and optimal operation of ethylene plant, realize intrinsic safety and improve market competitiveness.