In order to investigate soliton phenomenon in optical fiber induced by the dispersion and nonlinearity with structure of double pitfalls, the (1+1)-dimensional nonlinear Schr?dinger (NLS) equation with variable coefficients was discussed by employing a numerical split-step Fourier code. There exist a series of interesting properties of optical fiber solitons in two types of optical nonlinear systems with the structure of double pitfalls, such as the periodic oscillations of one soliton pulse induced by the nonlinear structure of double pitfalls based on the variable parameter background, the walk-off effect of two solitons induced by the nonlinear structure of double pitfalls based on the constant parameter background, the special interaction and the fusion reactions of three solitons in two types of optical nonlinear systems with the structure of double pitfalls.